This update provides:
1)  workaround around the build failures. In
summary, it forces the download of some packages during the build
process.
2) update the set of packages that should go inside the vendor
directory
3) Update the dockerfile to use go 1.10

Change-Id: I2bfd090ce0f25b0c10aa214755ae2da7e5384d60
diff --git a/vendor/github.com/gorilla/websocket/.gitignore b/vendor/github.com/gorilla/websocket/.gitignore
new file mode 100644
index 0000000..cd3fcd1
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/.gitignore
@@ -0,0 +1,25 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+
+.idea/
+*.iml
diff --git a/vendor/github.com/gorilla/websocket/.travis.yml b/vendor/github.com/gorilla/websocket/.travis.yml
new file mode 100644
index 0000000..a49db51
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/.travis.yml
@@ -0,0 +1,19 @@
+language: go
+sudo: false
+
+matrix:
+  include:
+    - go: 1.7.x
+    - go: 1.8.x
+    - go: 1.9.x
+    - go: 1.10.x
+    - go: 1.11.x
+    - go: tip
+  allow_failures:
+    - go: tip
+
+script:
+  - go get -t -v ./...
+  - diff -u <(echo -n) <(gofmt -d .)
+  - go vet $(go list ./... | grep -v /vendor/)
+  - go test -v -race ./...
diff --git a/vendor/github.com/gorilla/websocket/AUTHORS b/vendor/github.com/gorilla/websocket/AUTHORS
new file mode 100644
index 0000000..1931f40
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/AUTHORS
@@ -0,0 +1,9 @@
+# This is the official list of Gorilla WebSocket authors for copyright
+# purposes.
+#
+# Please keep the list sorted.
+
+Gary Burd <gary@beagledreams.com>
+Google LLC (https://opensource.google.com/)
+Joachim Bauch <mail@joachim-bauch.de>
+
diff --git a/vendor/github.com/gorilla/websocket/LICENSE b/vendor/github.com/gorilla/websocket/LICENSE
new file mode 100644
index 0000000..9171c97
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/LICENSE
@@ -0,0 +1,22 @@
+Copyright (c) 2013 The Gorilla WebSocket Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+  Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+  Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/gorilla/websocket/README.md b/vendor/github.com/gorilla/websocket/README.md
new file mode 100644
index 0000000..20e391f
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/README.md
@@ -0,0 +1,64 @@
+# Gorilla WebSocket
+
+Gorilla WebSocket is a [Go](http://golang.org/) implementation of the
+[WebSocket](http://www.rfc-editor.org/rfc/rfc6455.txt) protocol.
+
+[![Build Status](https://travis-ci.org/gorilla/websocket.svg?branch=master)](https://travis-ci.org/gorilla/websocket)
+[![GoDoc](https://godoc.org/github.com/gorilla/websocket?status.svg)](https://godoc.org/github.com/gorilla/websocket)
+
+### Documentation
+
+* [API Reference](http://godoc.org/github.com/gorilla/websocket)
+* [Chat example](https://github.com/gorilla/websocket/tree/master/examples/chat)
+* [Command example](https://github.com/gorilla/websocket/tree/master/examples/command)
+* [Client and server example](https://github.com/gorilla/websocket/tree/master/examples/echo)
+* [File watch example](https://github.com/gorilla/websocket/tree/master/examples/filewatch)
+
+### Status
+
+The Gorilla WebSocket package provides a complete and tested implementation of
+the [WebSocket](http://www.rfc-editor.org/rfc/rfc6455.txt) protocol. The
+package API is stable.
+
+### Installation
+
+    go get github.com/gorilla/websocket
+
+### Protocol Compliance
+
+The Gorilla WebSocket package passes the server tests in the [Autobahn Test
+Suite](http://autobahn.ws/testsuite) using the application in the [examples/autobahn
+subdirectory](https://github.com/gorilla/websocket/tree/master/examples/autobahn).
+
+### Gorilla WebSocket compared with other packages
+
+<table>
+<tr>
+<th></th>
+<th><a href="http://godoc.org/github.com/gorilla/websocket">github.com/gorilla</a></th>
+<th><a href="http://godoc.org/golang.org/x/net/websocket">golang.org/x/net</a></th>
+</tr>
+<tr>
+<tr><td colspan="3"><a href="http://tools.ietf.org/html/rfc6455">RFC 6455</a> Features</td></tr>
+<tr><td>Passes <a href="http://autobahn.ws/testsuite/">Autobahn Test Suite</a></td><td><a href="https://github.com/gorilla/websocket/tree/master/examples/autobahn">Yes</a></td><td>No</td></tr>
+<tr><td>Receive <a href="https://tools.ietf.org/html/rfc6455#section-5.4">fragmented</a> message<td>Yes</td><td><a href="https://code.google.com/p/go/issues/detail?id=7632">No</a>, see note 1</td></tr>
+<tr><td>Send <a href="https://tools.ietf.org/html/rfc6455#section-5.5.1">close</a> message</td><td><a href="http://godoc.org/github.com/gorilla/websocket#hdr-Control_Messages">Yes</a></td><td><a href="https://code.google.com/p/go/issues/detail?id=4588">No</a></td></tr>
+<tr><td>Send <a href="https://tools.ietf.org/html/rfc6455#section-5.5.2">pings</a> and receive <a href="https://tools.ietf.org/html/rfc6455#section-5.5.3">pongs</a></td><td><a href="http://godoc.org/github.com/gorilla/websocket#hdr-Control_Messages">Yes</a></td><td>No</td></tr>
+<tr><td>Get the <a href="https://tools.ietf.org/html/rfc6455#section-5.6">type</a> of a received data message</td><td>Yes</td><td>Yes, see note 2</td></tr>
+<tr><td colspan="3">Other Features</tr></td>
+<tr><td><a href="https://tools.ietf.org/html/rfc7692">Compression Extensions</a></td><td>Experimental</td><td>No</td></tr>
+<tr><td>Read message using io.Reader</td><td><a href="http://godoc.org/github.com/gorilla/websocket#Conn.NextReader">Yes</a></td><td>No, see note 3</td></tr>
+<tr><td>Write message using io.WriteCloser</td><td><a href="http://godoc.org/github.com/gorilla/websocket#Conn.NextWriter">Yes</a></td><td>No, see note 3</td></tr>
+</table>
+
+Notes:
+
+1. Large messages are fragmented in [Chrome's new WebSocket implementation](http://www.ietf.org/mail-archive/web/hybi/current/msg10503.html).
+2. The application can get the type of a received data message by implementing
+   a [Codec marshal](http://godoc.org/golang.org/x/net/websocket#Codec.Marshal)
+   function.
+3. The go.net io.Reader and io.Writer operate across WebSocket frame boundaries.
+  Read returns when the input buffer is full or a frame boundary is
+  encountered. Each call to Write sends a single frame message. The Gorilla
+  io.Reader and io.WriteCloser operate on a single WebSocket message.
+
diff --git a/vendor/github.com/gorilla/websocket/client.go b/vendor/github.com/gorilla/websocket/client.go
new file mode 100644
index 0000000..2e32fd5
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/client.go
@@ -0,0 +1,395 @@
+// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"bytes"
+	"context"
+	"crypto/tls"
+	"errors"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/http/httptrace"
+	"net/url"
+	"strings"
+	"time"
+)
+
+// ErrBadHandshake is returned when the server response to opening handshake is
+// invalid.
+var ErrBadHandshake = errors.New("websocket: bad handshake")
+
+var errInvalidCompression = errors.New("websocket: invalid compression negotiation")
+
+// NewClient creates a new client connection using the given net connection.
+// The URL u specifies the host and request URI. Use requestHeader to specify
+// the origin (Origin), subprotocols (Sec-WebSocket-Protocol) and cookies
+// (Cookie). Use the response.Header to get the selected subprotocol
+// (Sec-WebSocket-Protocol) and cookies (Set-Cookie).
+//
+// If the WebSocket handshake fails, ErrBadHandshake is returned along with a
+// non-nil *http.Response so that callers can handle redirects, authentication,
+// etc.
+//
+// Deprecated: Use Dialer instead.
+func NewClient(netConn net.Conn, u *url.URL, requestHeader http.Header, readBufSize, writeBufSize int) (c *Conn, response *http.Response, err error) {
+	d := Dialer{
+		ReadBufferSize:  readBufSize,
+		WriteBufferSize: writeBufSize,
+		NetDial: func(net, addr string) (net.Conn, error) {
+			return netConn, nil
+		},
+	}
+	return d.Dial(u.String(), requestHeader)
+}
+
+// A Dialer contains options for connecting to WebSocket server.
+type Dialer struct {
+	// NetDial specifies the dial function for creating TCP connections. If
+	// NetDial is nil, net.Dial is used.
+	NetDial func(network, addr string) (net.Conn, error)
+
+	// NetDialContext specifies the dial function for creating TCP connections. If
+	// NetDialContext is nil, net.DialContext is used.
+	NetDialContext func(ctx context.Context, network, addr string) (net.Conn, error)
+
+	// Proxy specifies a function to return a proxy for a given
+	// Request. If the function returns a non-nil error, the
+	// request is aborted with the provided error.
+	// If Proxy is nil or returns a nil *URL, no proxy is used.
+	Proxy func(*http.Request) (*url.URL, error)
+
+	// TLSClientConfig specifies the TLS configuration to use with tls.Client.
+	// If nil, the default configuration is used.
+	TLSClientConfig *tls.Config
+
+	// HandshakeTimeout specifies the duration for the handshake to complete.
+	HandshakeTimeout time.Duration
+
+	// ReadBufferSize and WriteBufferSize specify I/O buffer sizes. If a buffer
+	// size is zero, then a useful default size is used. The I/O buffer sizes
+	// do not limit the size of the messages that can be sent or received.
+	ReadBufferSize, WriteBufferSize int
+
+	// WriteBufferPool is a pool of buffers for write operations. If the value
+	// is not set, then write buffers are allocated to the connection for the
+	// lifetime of the connection.
+	//
+	// A pool is most useful when the application has a modest volume of writes
+	// across a large number of connections.
+	//
+	// Applications should use a single pool for each unique value of
+	// WriteBufferSize.
+	WriteBufferPool BufferPool
+
+	// Subprotocols specifies the client's requested subprotocols.
+	Subprotocols []string
+
+	// EnableCompression specifies if the client should attempt to negotiate
+	// per message compression (RFC 7692). Setting this value to true does not
+	// guarantee that compression will be supported. Currently only "no context
+	// takeover" modes are supported.
+	EnableCompression bool
+
+	// Jar specifies the cookie jar.
+	// If Jar is nil, cookies are not sent in requests and ignored
+	// in responses.
+	Jar http.CookieJar
+}
+
+// Dial creates a new client connection by calling DialContext with a background context.
+func (d *Dialer) Dial(urlStr string, requestHeader http.Header) (*Conn, *http.Response, error) {
+	return d.DialContext(context.Background(), urlStr, requestHeader)
+}
+
+var errMalformedURL = errors.New("malformed ws or wss URL")
+
+func hostPortNoPort(u *url.URL) (hostPort, hostNoPort string) {
+	hostPort = u.Host
+	hostNoPort = u.Host
+	if i := strings.LastIndex(u.Host, ":"); i > strings.LastIndex(u.Host, "]") {
+		hostNoPort = hostNoPort[:i]
+	} else {
+		switch u.Scheme {
+		case "wss":
+			hostPort += ":443"
+		case "https":
+			hostPort += ":443"
+		default:
+			hostPort += ":80"
+		}
+	}
+	return hostPort, hostNoPort
+}
+
+// DefaultDialer is a dialer with all fields set to the default values.
+var DefaultDialer = &Dialer{
+	Proxy:            http.ProxyFromEnvironment,
+	HandshakeTimeout: 45 * time.Second,
+}
+
+// nilDialer is dialer to use when receiver is nil.
+var nilDialer = *DefaultDialer
+
+// DialContext creates a new client connection. Use requestHeader to specify the
+// origin (Origin), subprotocols (Sec-WebSocket-Protocol) and cookies (Cookie).
+// Use the response.Header to get the selected subprotocol
+// (Sec-WebSocket-Protocol) and cookies (Set-Cookie).
+//
+// The context will be used in the request and in the Dialer
+//
+// If the WebSocket handshake fails, ErrBadHandshake is returned along with a
+// non-nil *http.Response so that callers can handle redirects, authentication,
+// etcetera. The response body may not contain the entire response and does not
+// need to be closed by the application.
+func (d *Dialer) DialContext(ctx context.Context, urlStr string, requestHeader http.Header) (*Conn, *http.Response, error) {
+	if d == nil {
+		d = &nilDialer
+	}
+
+	challengeKey, err := generateChallengeKey()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	u, err := url.Parse(urlStr)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	switch u.Scheme {
+	case "ws":
+		u.Scheme = "http"
+	case "wss":
+		u.Scheme = "https"
+	default:
+		return nil, nil, errMalformedURL
+	}
+
+	if u.User != nil {
+		// User name and password are not allowed in websocket URIs.
+		return nil, nil, errMalformedURL
+	}
+
+	req := &http.Request{
+		Method:     "GET",
+		URL:        u,
+		Proto:      "HTTP/1.1",
+		ProtoMajor: 1,
+		ProtoMinor: 1,
+		Header:     make(http.Header),
+		Host:       u.Host,
+	}
+	req = req.WithContext(ctx)
+
+	// Set the cookies present in the cookie jar of the dialer
+	if d.Jar != nil {
+		for _, cookie := range d.Jar.Cookies(u) {
+			req.AddCookie(cookie)
+		}
+	}
+
+	// Set the request headers using the capitalization for names and values in
+	// RFC examples. Although the capitalization shouldn't matter, there are
+	// servers that depend on it. The Header.Set method is not used because the
+	// method canonicalizes the header names.
+	req.Header["Upgrade"] = []string{"websocket"}
+	req.Header["Connection"] = []string{"Upgrade"}
+	req.Header["Sec-WebSocket-Key"] = []string{challengeKey}
+	req.Header["Sec-WebSocket-Version"] = []string{"13"}
+	if len(d.Subprotocols) > 0 {
+		req.Header["Sec-WebSocket-Protocol"] = []string{strings.Join(d.Subprotocols, ", ")}
+	}
+	for k, vs := range requestHeader {
+		switch {
+		case k == "Host":
+			if len(vs) > 0 {
+				req.Host = vs[0]
+			}
+		case k == "Upgrade" ||
+			k == "Connection" ||
+			k == "Sec-Websocket-Key" ||
+			k == "Sec-Websocket-Version" ||
+			k == "Sec-Websocket-Extensions" ||
+			(k == "Sec-Websocket-Protocol" && len(d.Subprotocols) > 0):
+			return nil, nil, errors.New("websocket: duplicate header not allowed: " + k)
+		case k == "Sec-Websocket-Protocol":
+			req.Header["Sec-WebSocket-Protocol"] = vs
+		default:
+			req.Header[k] = vs
+		}
+	}
+
+	if d.EnableCompression {
+		req.Header["Sec-WebSocket-Extensions"] = []string{"permessage-deflate; server_no_context_takeover; client_no_context_takeover"}
+	}
+
+	if d.HandshakeTimeout != 0 {
+		var cancel func()
+		ctx, cancel = context.WithTimeout(ctx, d.HandshakeTimeout)
+		defer cancel()
+	}
+
+	// Get network dial function.
+	var netDial func(network, add string) (net.Conn, error)
+
+	if d.NetDialContext != nil {
+		netDial = func(network, addr string) (net.Conn, error) {
+			return d.NetDialContext(ctx, network, addr)
+		}
+	} else if d.NetDial != nil {
+		netDial = d.NetDial
+	} else {
+		netDialer := &net.Dialer{}
+		netDial = func(network, addr string) (net.Conn, error) {
+			return netDialer.DialContext(ctx, network, addr)
+		}
+	}
+
+	// If needed, wrap the dial function to set the connection deadline.
+	if deadline, ok := ctx.Deadline(); ok {
+		forwardDial := netDial
+		netDial = func(network, addr string) (net.Conn, error) {
+			c, err := forwardDial(network, addr)
+			if err != nil {
+				return nil, err
+			}
+			err = c.SetDeadline(deadline)
+			if err != nil {
+				c.Close()
+				return nil, err
+			}
+			return c, nil
+		}
+	}
+
+	// If needed, wrap the dial function to connect through a proxy.
+	if d.Proxy != nil {
+		proxyURL, err := d.Proxy(req)
+		if err != nil {
+			return nil, nil, err
+		}
+		if proxyURL != nil {
+			dialer, err := proxy_FromURL(proxyURL, netDialerFunc(netDial))
+			if err != nil {
+				return nil, nil, err
+			}
+			netDial = dialer.Dial
+		}
+	}
+
+	hostPort, hostNoPort := hostPortNoPort(u)
+	trace := httptrace.ContextClientTrace(ctx)
+	if trace != nil && trace.GetConn != nil {
+		trace.GetConn(hostPort)
+	}
+
+	netConn, err := netDial("tcp", hostPort)
+	if trace != nil && trace.GotConn != nil {
+		trace.GotConn(httptrace.GotConnInfo{
+			Conn: netConn,
+		})
+	}
+	if err != nil {
+		return nil, nil, err
+	}
+
+	defer func() {
+		if netConn != nil {
+			netConn.Close()
+		}
+	}()
+
+	if u.Scheme == "https" {
+		cfg := cloneTLSConfig(d.TLSClientConfig)
+		if cfg.ServerName == "" {
+			cfg.ServerName = hostNoPort
+		}
+		tlsConn := tls.Client(netConn, cfg)
+		netConn = tlsConn
+
+		var err error
+		if trace != nil {
+			err = doHandshakeWithTrace(trace, tlsConn, cfg)
+		} else {
+			err = doHandshake(tlsConn, cfg)
+		}
+
+		if err != nil {
+			return nil, nil, err
+		}
+	}
+
+	conn := newConn(netConn, false, d.ReadBufferSize, d.WriteBufferSize, d.WriteBufferPool, nil, nil)
+
+	if err := req.Write(netConn); err != nil {
+		return nil, nil, err
+	}
+
+	if trace != nil && trace.GotFirstResponseByte != nil {
+		if peek, err := conn.br.Peek(1); err == nil && len(peek) == 1 {
+			trace.GotFirstResponseByte()
+		}
+	}
+
+	resp, err := http.ReadResponse(conn.br, req)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if d.Jar != nil {
+		if rc := resp.Cookies(); len(rc) > 0 {
+			d.Jar.SetCookies(u, rc)
+		}
+	}
+
+	if resp.StatusCode != 101 ||
+		!strings.EqualFold(resp.Header.Get("Upgrade"), "websocket") ||
+		!strings.EqualFold(resp.Header.Get("Connection"), "upgrade") ||
+		resp.Header.Get("Sec-Websocket-Accept") != computeAcceptKey(challengeKey) {
+		// Before closing the network connection on return from this
+		// function, slurp up some of the response to aid application
+		// debugging.
+		buf := make([]byte, 1024)
+		n, _ := io.ReadFull(resp.Body, buf)
+		resp.Body = ioutil.NopCloser(bytes.NewReader(buf[:n]))
+		return nil, resp, ErrBadHandshake
+	}
+
+	for _, ext := range parseExtensions(resp.Header) {
+		if ext[""] != "permessage-deflate" {
+			continue
+		}
+		_, snct := ext["server_no_context_takeover"]
+		_, cnct := ext["client_no_context_takeover"]
+		if !snct || !cnct {
+			return nil, resp, errInvalidCompression
+		}
+		conn.newCompressionWriter = compressNoContextTakeover
+		conn.newDecompressionReader = decompressNoContextTakeover
+		break
+	}
+
+	resp.Body = ioutil.NopCloser(bytes.NewReader([]byte{}))
+	conn.subprotocol = resp.Header.Get("Sec-Websocket-Protocol")
+
+	netConn.SetDeadline(time.Time{})
+	netConn = nil // to avoid close in defer.
+	return conn, resp, nil
+}
+
+func doHandshake(tlsConn *tls.Conn, cfg *tls.Config) error {
+	if err := tlsConn.Handshake(); err != nil {
+		return err
+	}
+	if !cfg.InsecureSkipVerify {
+		if err := tlsConn.VerifyHostname(cfg.ServerName); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/vendor/github.com/gorilla/websocket/client_clone.go b/vendor/github.com/gorilla/websocket/client_clone.go
new file mode 100644
index 0000000..4f0d943
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/client_clone.go
@@ -0,0 +1,16 @@
+// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build go1.8
+
+package websocket
+
+import "crypto/tls"
+
+func cloneTLSConfig(cfg *tls.Config) *tls.Config {
+	if cfg == nil {
+		return &tls.Config{}
+	}
+	return cfg.Clone()
+}
diff --git a/vendor/github.com/gorilla/websocket/client_clone_legacy.go b/vendor/github.com/gorilla/websocket/client_clone_legacy.go
new file mode 100644
index 0000000..babb007
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/client_clone_legacy.go
@@ -0,0 +1,38 @@
+// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !go1.8
+
+package websocket
+
+import "crypto/tls"
+
+// cloneTLSConfig clones all public fields except the fields
+// SessionTicketsDisabled and SessionTicketKey. This avoids copying the
+// sync.Mutex in the sync.Once and makes it safe to call cloneTLSConfig on a
+// config in active use.
+func cloneTLSConfig(cfg *tls.Config) *tls.Config {
+	if cfg == nil {
+		return &tls.Config{}
+	}
+	return &tls.Config{
+		Rand:                     cfg.Rand,
+		Time:                     cfg.Time,
+		Certificates:             cfg.Certificates,
+		NameToCertificate:        cfg.NameToCertificate,
+		GetCertificate:           cfg.GetCertificate,
+		RootCAs:                  cfg.RootCAs,
+		NextProtos:               cfg.NextProtos,
+		ServerName:               cfg.ServerName,
+		ClientAuth:               cfg.ClientAuth,
+		ClientCAs:                cfg.ClientCAs,
+		InsecureSkipVerify:       cfg.InsecureSkipVerify,
+		CipherSuites:             cfg.CipherSuites,
+		PreferServerCipherSuites: cfg.PreferServerCipherSuites,
+		ClientSessionCache:       cfg.ClientSessionCache,
+		MinVersion:               cfg.MinVersion,
+		MaxVersion:               cfg.MaxVersion,
+		CurvePreferences:         cfg.CurvePreferences,
+	}
+}
diff --git a/vendor/github.com/gorilla/websocket/compression.go b/vendor/github.com/gorilla/websocket/compression.go
new file mode 100644
index 0000000..813ffb1
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/compression.go
@@ -0,0 +1,148 @@
+// Copyright 2017 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"compress/flate"
+	"errors"
+	"io"
+	"strings"
+	"sync"
+)
+
+const (
+	minCompressionLevel     = -2 // flate.HuffmanOnly not defined in Go < 1.6
+	maxCompressionLevel     = flate.BestCompression
+	defaultCompressionLevel = 1
+)
+
+var (
+	flateWriterPools [maxCompressionLevel - minCompressionLevel + 1]sync.Pool
+	flateReaderPool  = sync.Pool{New: func() interface{} {
+		return flate.NewReader(nil)
+	}}
+)
+
+func decompressNoContextTakeover(r io.Reader) io.ReadCloser {
+	const tail =
+	// Add four bytes as specified in RFC
+	"\x00\x00\xff\xff" +
+		// Add final block to squelch unexpected EOF error from flate reader.
+		"\x01\x00\x00\xff\xff"
+
+	fr, _ := flateReaderPool.Get().(io.ReadCloser)
+	fr.(flate.Resetter).Reset(io.MultiReader(r, strings.NewReader(tail)), nil)
+	return &flateReadWrapper{fr}
+}
+
+func isValidCompressionLevel(level int) bool {
+	return minCompressionLevel <= level && level <= maxCompressionLevel
+}
+
+func compressNoContextTakeover(w io.WriteCloser, level int) io.WriteCloser {
+	p := &flateWriterPools[level-minCompressionLevel]
+	tw := &truncWriter{w: w}
+	fw, _ := p.Get().(*flate.Writer)
+	if fw == nil {
+		fw, _ = flate.NewWriter(tw, level)
+	} else {
+		fw.Reset(tw)
+	}
+	return &flateWriteWrapper{fw: fw, tw: tw, p: p}
+}
+
+// truncWriter is an io.Writer that writes all but the last four bytes of the
+// stream to another io.Writer.
+type truncWriter struct {
+	w io.WriteCloser
+	n int
+	p [4]byte
+}
+
+func (w *truncWriter) Write(p []byte) (int, error) {
+	n := 0
+
+	// fill buffer first for simplicity.
+	if w.n < len(w.p) {
+		n = copy(w.p[w.n:], p)
+		p = p[n:]
+		w.n += n
+		if len(p) == 0 {
+			return n, nil
+		}
+	}
+
+	m := len(p)
+	if m > len(w.p) {
+		m = len(w.p)
+	}
+
+	if nn, err := w.w.Write(w.p[:m]); err != nil {
+		return n + nn, err
+	}
+
+	copy(w.p[:], w.p[m:])
+	copy(w.p[len(w.p)-m:], p[len(p)-m:])
+	nn, err := w.w.Write(p[:len(p)-m])
+	return n + nn, err
+}
+
+type flateWriteWrapper struct {
+	fw *flate.Writer
+	tw *truncWriter
+	p  *sync.Pool
+}
+
+func (w *flateWriteWrapper) Write(p []byte) (int, error) {
+	if w.fw == nil {
+		return 0, errWriteClosed
+	}
+	return w.fw.Write(p)
+}
+
+func (w *flateWriteWrapper) Close() error {
+	if w.fw == nil {
+		return errWriteClosed
+	}
+	err1 := w.fw.Flush()
+	w.p.Put(w.fw)
+	w.fw = nil
+	if w.tw.p != [4]byte{0, 0, 0xff, 0xff} {
+		return errors.New("websocket: internal error, unexpected bytes at end of flate stream")
+	}
+	err2 := w.tw.w.Close()
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+type flateReadWrapper struct {
+	fr io.ReadCloser
+}
+
+func (r *flateReadWrapper) Read(p []byte) (int, error) {
+	if r.fr == nil {
+		return 0, io.ErrClosedPipe
+	}
+	n, err := r.fr.Read(p)
+	if err == io.EOF {
+		// Preemptively place the reader back in the pool. This helps with
+		// scenarios where the application does not call NextReader() soon after
+		// this final read.
+		r.Close()
+	}
+	return n, err
+}
+
+func (r *flateReadWrapper) Close() error {
+	if r.fr == nil {
+		return io.ErrClosedPipe
+	}
+	err := r.fr.Close()
+	flateReaderPool.Put(r.fr)
+	r.fr = nil
+	return err
+}
diff --git a/vendor/github.com/gorilla/websocket/conn.go b/vendor/github.com/gorilla/websocket/conn.go
new file mode 100644
index 0000000..d2a21c1
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/conn.go
@@ -0,0 +1,1165 @@
+// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"bufio"
+	"encoding/binary"
+	"errors"
+	"io"
+	"io/ioutil"
+	"math/rand"
+	"net"
+	"strconv"
+	"sync"
+	"time"
+	"unicode/utf8"
+)
+
+const (
+	// Frame header byte 0 bits from Section 5.2 of RFC 6455
+	finalBit = 1 << 7
+	rsv1Bit  = 1 << 6
+	rsv2Bit  = 1 << 5
+	rsv3Bit  = 1 << 4
+
+	// Frame header byte 1 bits from Section 5.2 of RFC 6455
+	maskBit = 1 << 7
+
+	maxFrameHeaderSize         = 2 + 8 + 4 // Fixed header + length + mask
+	maxControlFramePayloadSize = 125
+
+	writeWait = time.Second
+
+	defaultReadBufferSize  = 4096
+	defaultWriteBufferSize = 4096
+
+	continuationFrame = 0
+	noFrame           = -1
+)
+
+// Close codes defined in RFC 6455, section 11.7.
+const (
+	CloseNormalClosure           = 1000
+	CloseGoingAway               = 1001
+	CloseProtocolError           = 1002
+	CloseUnsupportedData         = 1003
+	CloseNoStatusReceived        = 1005
+	CloseAbnormalClosure         = 1006
+	CloseInvalidFramePayloadData = 1007
+	ClosePolicyViolation         = 1008
+	CloseMessageTooBig           = 1009
+	CloseMandatoryExtension      = 1010
+	CloseInternalServerErr       = 1011
+	CloseServiceRestart          = 1012
+	CloseTryAgainLater           = 1013
+	CloseTLSHandshake            = 1015
+)
+
+// The message types are defined in RFC 6455, section 11.8.
+const (
+	// TextMessage denotes a text data message. The text message payload is
+	// interpreted as UTF-8 encoded text data.
+	TextMessage = 1
+
+	// BinaryMessage denotes a binary data message.
+	BinaryMessage = 2
+
+	// CloseMessage denotes a close control message. The optional message
+	// payload contains a numeric code and text. Use the FormatCloseMessage
+	// function to format a close message payload.
+	CloseMessage = 8
+
+	// PingMessage denotes a ping control message. The optional message payload
+	// is UTF-8 encoded text.
+	PingMessage = 9
+
+	// PongMessage denotes a pong control message. The optional message payload
+	// is UTF-8 encoded text.
+	PongMessage = 10
+)
+
+// ErrCloseSent is returned when the application writes a message to the
+// connection after sending a close message.
+var ErrCloseSent = errors.New("websocket: close sent")
+
+// ErrReadLimit is returned when reading a message that is larger than the
+// read limit set for the connection.
+var ErrReadLimit = errors.New("websocket: read limit exceeded")
+
+// netError satisfies the net Error interface.
+type netError struct {
+	msg       string
+	temporary bool
+	timeout   bool
+}
+
+func (e *netError) Error() string   { return e.msg }
+func (e *netError) Temporary() bool { return e.temporary }
+func (e *netError) Timeout() bool   { return e.timeout }
+
+// CloseError represents a close message.
+type CloseError struct {
+	// Code is defined in RFC 6455, section 11.7.
+	Code int
+
+	// Text is the optional text payload.
+	Text string
+}
+
+func (e *CloseError) Error() string {
+	s := []byte("websocket: close ")
+	s = strconv.AppendInt(s, int64(e.Code), 10)
+	switch e.Code {
+	case CloseNormalClosure:
+		s = append(s, " (normal)"...)
+	case CloseGoingAway:
+		s = append(s, " (going away)"...)
+	case CloseProtocolError:
+		s = append(s, " (protocol error)"...)
+	case CloseUnsupportedData:
+		s = append(s, " (unsupported data)"...)
+	case CloseNoStatusReceived:
+		s = append(s, " (no status)"...)
+	case CloseAbnormalClosure:
+		s = append(s, " (abnormal closure)"...)
+	case CloseInvalidFramePayloadData:
+		s = append(s, " (invalid payload data)"...)
+	case ClosePolicyViolation:
+		s = append(s, " (policy violation)"...)
+	case CloseMessageTooBig:
+		s = append(s, " (message too big)"...)
+	case CloseMandatoryExtension:
+		s = append(s, " (mandatory extension missing)"...)
+	case CloseInternalServerErr:
+		s = append(s, " (internal server error)"...)
+	case CloseTLSHandshake:
+		s = append(s, " (TLS handshake error)"...)
+	}
+	if e.Text != "" {
+		s = append(s, ": "...)
+		s = append(s, e.Text...)
+	}
+	return string(s)
+}
+
+// IsCloseError returns boolean indicating whether the error is a *CloseError
+// with one of the specified codes.
+func IsCloseError(err error, codes ...int) bool {
+	if e, ok := err.(*CloseError); ok {
+		for _, code := range codes {
+			if e.Code == code {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// IsUnexpectedCloseError returns boolean indicating whether the error is a
+// *CloseError with a code not in the list of expected codes.
+func IsUnexpectedCloseError(err error, expectedCodes ...int) bool {
+	if e, ok := err.(*CloseError); ok {
+		for _, code := range expectedCodes {
+			if e.Code == code {
+				return false
+			}
+		}
+		return true
+	}
+	return false
+}
+
+var (
+	errWriteTimeout        = &netError{msg: "websocket: write timeout", timeout: true, temporary: true}
+	errUnexpectedEOF       = &CloseError{Code: CloseAbnormalClosure, Text: io.ErrUnexpectedEOF.Error()}
+	errBadWriteOpCode      = errors.New("websocket: bad write message type")
+	errWriteClosed         = errors.New("websocket: write closed")
+	errInvalidControlFrame = errors.New("websocket: invalid control frame")
+)
+
+func newMaskKey() [4]byte {
+	n := rand.Uint32()
+	return [4]byte{byte(n), byte(n >> 8), byte(n >> 16), byte(n >> 24)}
+}
+
+func hideTempErr(err error) error {
+	if e, ok := err.(net.Error); ok && e.Temporary() {
+		err = &netError{msg: e.Error(), timeout: e.Timeout()}
+	}
+	return err
+}
+
+func isControl(frameType int) bool {
+	return frameType == CloseMessage || frameType == PingMessage || frameType == PongMessage
+}
+
+func isData(frameType int) bool {
+	return frameType == TextMessage || frameType == BinaryMessage
+}
+
+var validReceivedCloseCodes = map[int]bool{
+	// see http://www.iana.org/assignments/websocket/websocket.xhtml#close-code-number
+
+	CloseNormalClosure:           true,
+	CloseGoingAway:               true,
+	CloseProtocolError:           true,
+	CloseUnsupportedData:         true,
+	CloseNoStatusReceived:        false,
+	CloseAbnormalClosure:         false,
+	CloseInvalidFramePayloadData: true,
+	ClosePolicyViolation:         true,
+	CloseMessageTooBig:           true,
+	CloseMandatoryExtension:      true,
+	CloseInternalServerErr:       true,
+	CloseServiceRestart:          true,
+	CloseTryAgainLater:           true,
+	CloseTLSHandshake:            false,
+}
+
+func isValidReceivedCloseCode(code int) bool {
+	return validReceivedCloseCodes[code] || (code >= 3000 && code <= 4999)
+}
+
+// BufferPool represents a pool of buffers. The *sync.Pool type satisfies this
+// interface.  The type of the value stored in a pool is not specified.
+type BufferPool interface {
+	// Get gets a value from the pool or returns nil if the pool is empty.
+	Get() interface{}
+	// Put adds a value to the pool.
+	Put(interface{})
+}
+
+// writePoolData is the type added to the write buffer pool. This wrapper is
+// used to prevent applications from peeking at and depending on the values
+// added to the pool.
+type writePoolData struct{ buf []byte }
+
+// The Conn type represents a WebSocket connection.
+type Conn struct {
+	conn        net.Conn
+	isServer    bool
+	subprotocol string
+
+	// Write fields
+	mu            chan bool // used as mutex to protect write to conn
+	writeBuf      []byte    // frame is constructed in this buffer.
+	writePool     BufferPool
+	writeBufSize  int
+	writeDeadline time.Time
+	writer        io.WriteCloser // the current writer returned to the application
+	isWriting     bool           // for best-effort concurrent write detection
+
+	writeErrMu sync.Mutex
+	writeErr   error
+
+	enableWriteCompression bool
+	compressionLevel       int
+	newCompressionWriter   func(io.WriteCloser, int) io.WriteCloser
+
+	// Read fields
+	reader        io.ReadCloser // the current reader returned to the application
+	readErr       error
+	br            *bufio.Reader
+	readRemaining int64 // bytes remaining in current frame.
+	readFinal     bool  // true the current message has more frames.
+	readLength    int64 // Message size.
+	readLimit     int64 // Maximum message size.
+	readMaskPos   int
+	readMaskKey   [4]byte
+	handlePong    func(string) error
+	handlePing    func(string) error
+	handleClose   func(int, string) error
+	readErrCount  int
+	messageReader *messageReader // the current low-level reader
+
+	readDecompress         bool // whether last read frame had RSV1 set
+	newDecompressionReader func(io.Reader) io.ReadCloser
+}
+
+func newConn(conn net.Conn, isServer bool, readBufferSize, writeBufferSize int, writeBufferPool BufferPool, br *bufio.Reader, writeBuf []byte) *Conn {
+
+	if br == nil {
+		if readBufferSize == 0 {
+			readBufferSize = defaultReadBufferSize
+		} else if readBufferSize < maxControlFramePayloadSize {
+			// must be large enough for control frame
+			readBufferSize = maxControlFramePayloadSize
+		}
+		br = bufio.NewReaderSize(conn, readBufferSize)
+	}
+
+	if writeBufferSize <= 0 {
+		writeBufferSize = defaultWriteBufferSize
+	}
+	writeBufferSize += maxFrameHeaderSize
+
+	if writeBuf == nil && writeBufferPool == nil {
+		writeBuf = make([]byte, writeBufferSize)
+	}
+
+	mu := make(chan bool, 1)
+	mu <- true
+	c := &Conn{
+		isServer:               isServer,
+		br:                     br,
+		conn:                   conn,
+		mu:                     mu,
+		readFinal:              true,
+		writeBuf:               writeBuf,
+		writePool:              writeBufferPool,
+		writeBufSize:           writeBufferSize,
+		enableWriteCompression: true,
+		compressionLevel:       defaultCompressionLevel,
+	}
+	c.SetCloseHandler(nil)
+	c.SetPingHandler(nil)
+	c.SetPongHandler(nil)
+	return c
+}
+
+// Subprotocol returns the negotiated protocol for the connection.
+func (c *Conn) Subprotocol() string {
+	return c.subprotocol
+}
+
+// Close closes the underlying network connection without sending or waiting
+// for a close message.
+func (c *Conn) Close() error {
+	return c.conn.Close()
+}
+
+// LocalAddr returns the local network address.
+func (c *Conn) LocalAddr() net.Addr {
+	return c.conn.LocalAddr()
+}
+
+// RemoteAddr returns the remote network address.
+func (c *Conn) RemoteAddr() net.Addr {
+	return c.conn.RemoteAddr()
+}
+
+// Write methods
+
+func (c *Conn) writeFatal(err error) error {
+	err = hideTempErr(err)
+	c.writeErrMu.Lock()
+	if c.writeErr == nil {
+		c.writeErr = err
+	}
+	c.writeErrMu.Unlock()
+	return err
+}
+
+func (c *Conn) read(n int) ([]byte, error) {
+	p, err := c.br.Peek(n)
+	if err == io.EOF {
+		err = errUnexpectedEOF
+	}
+	c.br.Discard(len(p))
+	return p, err
+}
+
+func (c *Conn) write(frameType int, deadline time.Time, buf0, buf1 []byte) error {
+	<-c.mu
+	defer func() { c.mu <- true }()
+
+	c.writeErrMu.Lock()
+	err := c.writeErr
+	c.writeErrMu.Unlock()
+	if err != nil {
+		return err
+	}
+
+	c.conn.SetWriteDeadline(deadline)
+	if len(buf1) == 0 {
+		_, err = c.conn.Write(buf0)
+	} else {
+		err = c.writeBufs(buf0, buf1)
+	}
+	if err != nil {
+		return c.writeFatal(err)
+	}
+	if frameType == CloseMessage {
+		c.writeFatal(ErrCloseSent)
+	}
+	return nil
+}
+
+// WriteControl writes a control message with the given deadline. The allowed
+// message types are CloseMessage, PingMessage and PongMessage.
+func (c *Conn) WriteControl(messageType int, data []byte, deadline time.Time) error {
+	if !isControl(messageType) {
+		return errBadWriteOpCode
+	}
+	if len(data) > maxControlFramePayloadSize {
+		return errInvalidControlFrame
+	}
+
+	b0 := byte(messageType) | finalBit
+	b1 := byte(len(data))
+	if !c.isServer {
+		b1 |= maskBit
+	}
+
+	buf := make([]byte, 0, maxFrameHeaderSize+maxControlFramePayloadSize)
+	buf = append(buf, b0, b1)
+
+	if c.isServer {
+		buf = append(buf, data...)
+	} else {
+		key := newMaskKey()
+		buf = append(buf, key[:]...)
+		buf = append(buf, data...)
+		maskBytes(key, 0, buf[6:])
+	}
+
+	d := time.Hour * 1000
+	if !deadline.IsZero() {
+		d = deadline.Sub(time.Now())
+		if d < 0 {
+			return errWriteTimeout
+		}
+	}
+
+	timer := time.NewTimer(d)
+	select {
+	case <-c.mu:
+		timer.Stop()
+	case <-timer.C:
+		return errWriteTimeout
+	}
+	defer func() { c.mu <- true }()
+
+	c.writeErrMu.Lock()
+	err := c.writeErr
+	c.writeErrMu.Unlock()
+	if err != nil {
+		return err
+	}
+
+	c.conn.SetWriteDeadline(deadline)
+	_, err = c.conn.Write(buf)
+	if err != nil {
+		return c.writeFatal(err)
+	}
+	if messageType == CloseMessage {
+		c.writeFatal(ErrCloseSent)
+	}
+	return err
+}
+
+func (c *Conn) prepWrite(messageType int) error {
+	// Close previous writer if not already closed by the application. It's
+	// probably better to return an error in this situation, but we cannot
+	// change this without breaking existing applications.
+	if c.writer != nil {
+		c.writer.Close()
+		c.writer = nil
+	}
+
+	if !isControl(messageType) && !isData(messageType) {
+		return errBadWriteOpCode
+	}
+
+	c.writeErrMu.Lock()
+	err := c.writeErr
+	c.writeErrMu.Unlock()
+	if err != nil {
+		return err
+	}
+
+	if c.writeBuf == nil {
+		wpd, ok := c.writePool.Get().(writePoolData)
+		if ok {
+			c.writeBuf = wpd.buf
+		} else {
+			c.writeBuf = make([]byte, c.writeBufSize)
+		}
+	}
+	return nil
+}
+
+// NextWriter returns a writer for the next message to send. The writer's Close
+// method flushes the complete message to the network.
+//
+// There can be at most one open writer on a connection. NextWriter closes the
+// previous writer if the application has not already done so.
+//
+// All message types (TextMessage, BinaryMessage, CloseMessage, PingMessage and
+// PongMessage) are supported.
+func (c *Conn) NextWriter(messageType int) (io.WriteCloser, error) {
+	if err := c.prepWrite(messageType); err != nil {
+		return nil, err
+	}
+
+	mw := &messageWriter{
+		c:         c,
+		frameType: messageType,
+		pos:       maxFrameHeaderSize,
+	}
+	c.writer = mw
+	if c.newCompressionWriter != nil && c.enableWriteCompression && isData(messageType) {
+		w := c.newCompressionWriter(c.writer, c.compressionLevel)
+		mw.compress = true
+		c.writer = w
+	}
+	return c.writer, nil
+}
+
+type messageWriter struct {
+	c         *Conn
+	compress  bool // whether next call to flushFrame should set RSV1
+	pos       int  // end of data in writeBuf.
+	frameType int  // type of the current frame.
+	err       error
+}
+
+func (w *messageWriter) fatal(err error) error {
+	if w.err != nil {
+		w.err = err
+		w.c.writer = nil
+	}
+	return err
+}
+
+// flushFrame writes buffered data and extra as a frame to the network. The
+// final argument indicates that this is the last frame in the message.
+func (w *messageWriter) flushFrame(final bool, extra []byte) error {
+	c := w.c
+	length := w.pos - maxFrameHeaderSize + len(extra)
+
+	// Check for invalid control frames.
+	if isControl(w.frameType) &&
+		(!final || length > maxControlFramePayloadSize) {
+		return w.fatal(errInvalidControlFrame)
+	}
+
+	b0 := byte(w.frameType)
+	if final {
+		b0 |= finalBit
+	}
+	if w.compress {
+		b0 |= rsv1Bit
+	}
+	w.compress = false
+
+	b1 := byte(0)
+	if !c.isServer {
+		b1 |= maskBit
+	}
+
+	// Assume that the frame starts at beginning of c.writeBuf.
+	framePos := 0
+	if c.isServer {
+		// Adjust up if mask not included in the header.
+		framePos = 4
+	}
+
+	switch {
+	case length >= 65536:
+		c.writeBuf[framePos] = b0
+		c.writeBuf[framePos+1] = b1 | 127
+		binary.BigEndian.PutUint64(c.writeBuf[framePos+2:], uint64(length))
+	case length > 125:
+		framePos += 6
+		c.writeBuf[framePos] = b0
+		c.writeBuf[framePos+1] = b1 | 126
+		binary.BigEndian.PutUint16(c.writeBuf[framePos+2:], uint16(length))
+	default:
+		framePos += 8
+		c.writeBuf[framePos] = b0
+		c.writeBuf[framePos+1] = b1 | byte(length)
+	}
+
+	if !c.isServer {
+		key := newMaskKey()
+		copy(c.writeBuf[maxFrameHeaderSize-4:], key[:])
+		maskBytes(key, 0, c.writeBuf[maxFrameHeaderSize:w.pos])
+		if len(extra) > 0 {
+			return c.writeFatal(errors.New("websocket: internal error, extra used in client mode"))
+		}
+	}
+
+	// Write the buffers to the connection with best-effort detection of
+	// concurrent writes. See the concurrency section in the package
+	// documentation for more info.
+
+	if c.isWriting {
+		panic("concurrent write to websocket connection")
+	}
+	c.isWriting = true
+
+	err := c.write(w.frameType, c.writeDeadline, c.writeBuf[framePos:w.pos], extra)
+
+	if !c.isWriting {
+		panic("concurrent write to websocket connection")
+	}
+	c.isWriting = false
+
+	if err != nil {
+		return w.fatal(err)
+	}
+
+	if final {
+		c.writer = nil
+		if c.writePool != nil {
+			c.writePool.Put(writePoolData{buf: c.writeBuf})
+			c.writeBuf = nil
+		}
+		return nil
+	}
+
+	// Setup for next frame.
+	w.pos = maxFrameHeaderSize
+	w.frameType = continuationFrame
+	return nil
+}
+
+func (w *messageWriter) ncopy(max int) (int, error) {
+	n := len(w.c.writeBuf) - w.pos
+	if n <= 0 {
+		if err := w.flushFrame(false, nil); err != nil {
+			return 0, err
+		}
+		n = len(w.c.writeBuf) - w.pos
+	}
+	if n > max {
+		n = max
+	}
+	return n, nil
+}
+
+func (w *messageWriter) Write(p []byte) (int, error) {
+	if w.err != nil {
+		return 0, w.err
+	}
+
+	if len(p) > 2*len(w.c.writeBuf) && w.c.isServer {
+		// Don't buffer large messages.
+		err := w.flushFrame(false, p)
+		if err != nil {
+			return 0, err
+		}
+		return len(p), nil
+	}
+
+	nn := len(p)
+	for len(p) > 0 {
+		n, err := w.ncopy(len(p))
+		if err != nil {
+			return 0, err
+		}
+		copy(w.c.writeBuf[w.pos:], p[:n])
+		w.pos += n
+		p = p[n:]
+	}
+	return nn, nil
+}
+
+func (w *messageWriter) WriteString(p string) (int, error) {
+	if w.err != nil {
+		return 0, w.err
+	}
+
+	nn := len(p)
+	for len(p) > 0 {
+		n, err := w.ncopy(len(p))
+		if err != nil {
+			return 0, err
+		}
+		copy(w.c.writeBuf[w.pos:], p[:n])
+		w.pos += n
+		p = p[n:]
+	}
+	return nn, nil
+}
+
+func (w *messageWriter) ReadFrom(r io.Reader) (nn int64, err error) {
+	if w.err != nil {
+		return 0, w.err
+	}
+	for {
+		if w.pos == len(w.c.writeBuf) {
+			err = w.flushFrame(false, nil)
+			if err != nil {
+				break
+			}
+		}
+		var n int
+		n, err = r.Read(w.c.writeBuf[w.pos:])
+		w.pos += n
+		nn += int64(n)
+		if err != nil {
+			if err == io.EOF {
+				err = nil
+			}
+			break
+		}
+	}
+	return nn, err
+}
+
+func (w *messageWriter) Close() error {
+	if w.err != nil {
+		return w.err
+	}
+	if err := w.flushFrame(true, nil); err != nil {
+		return err
+	}
+	w.err = errWriteClosed
+	return nil
+}
+
+// WritePreparedMessage writes prepared message into connection.
+func (c *Conn) WritePreparedMessage(pm *PreparedMessage) error {
+	frameType, frameData, err := pm.frame(prepareKey{
+		isServer:         c.isServer,
+		compress:         c.newCompressionWriter != nil && c.enableWriteCompression && isData(pm.messageType),
+		compressionLevel: c.compressionLevel,
+	})
+	if err != nil {
+		return err
+	}
+	if c.isWriting {
+		panic("concurrent write to websocket connection")
+	}
+	c.isWriting = true
+	err = c.write(frameType, c.writeDeadline, frameData, nil)
+	if !c.isWriting {
+		panic("concurrent write to websocket connection")
+	}
+	c.isWriting = false
+	return err
+}
+
+// WriteMessage is a helper method for getting a writer using NextWriter,
+// writing the message and closing the writer.
+func (c *Conn) WriteMessage(messageType int, data []byte) error {
+
+	if c.isServer && (c.newCompressionWriter == nil || !c.enableWriteCompression) {
+		// Fast path with no allocations and single frame.
+
+		if err := c.prepWrite(messageType); err != nil {
+			return err
+		}
+		mw := messageWriter{c: c, frameType: messageType, pos: maxFrameHeaderSize}
+		n := copy(c.writeBuf[mw.pos:], data)
+		mw.pos += n
+		data = data[n:]
+		return mw.flushFrame(true, data)
+	}
+
+	w, err := c.NextWriter(messageType)
+	if err != nil {
+		return err
+	}
+	if _, err = w.Write(data); err != nil {
+		return err
+	}
+	return w.Close()
+}
+
+// SetWriteDeadline sets the write deadline on the underlying network
+// connection. After a write has timed out, the websocket state is corrupt and
+// all future writes will return an error. A zero value for t means writes will
+// not time out.
+func (c *Conn) SetWriteDeadline(t time.Time) error {
+	c.writeDeadline = t
+	return nil
+}
+
+// Read methods
+
+func (c *Conn) advanceFrame() (int, error) {
+	// 1. Skip remainder of previous frame.
+
+	if c.readRemaining > 0 {
+		if _, err := io.CopyN(ioutil.Discard, c.br, c.readRemaining); err != nil {
+			return noFrame, err
+		}
+	}
+
+	// 2. Read and parse first two bytes of frame header.
+
+	p, err := c.read(2)
+	if err != nil {
+		return noFrame, err
+	}
+
+	final := p[0]&finalBit != 0
+	frameType := int(p[0] & 0xf)
+	mask := p[1]&maskBit != 0
+	c.readRemaining = int64(p[1] & 0x7f)
+
+	c.readDecompress = false
+	if c.newDecompressionReader != nil && (p[0]&rsv1Bit) != 0 {
+		c.readDecompress = true
+		p[0] &^= rsv1Bit
+	}
+
+	if rsv := p[0] & (rsv1Bit | rsv2Bit | rsv3Bit); rsv != 0 {
+		return noFrame, c.handleProtocolError("unexpected reserved bits 0x" + strconv.FormatInt(int64(rsv), 16))
+	}
+
+	switch frameType {
+	case CloseMessage, PingMessage, PongMessage:
+		if c.readRemaining > maxControlFramePayloadSize {
+			return noFrame, c.handleProtocolError("control frame length > 125")
+		}
+		if !final {
+			return noFrame, c.handleProtocolError("control frame not final")
+		}
+	case TextMessage, BinaryMessage:
+		if !c.readFinal {
+			return noFrame, c.handleProtocolError("message start before final message frame")
+		}
+		c.readFinal = final
+	case continuationFrame:
+		if c.readFinal {
+			return noFrame, c.handleProtocolError("continuation after final message frame")
+		}
+		c.readFinal = final
+	default:
+		return noFrame, c.handleProtocolError("unknown opcode " + strconv.Itoa(frameType))
+	}
+
+	// 3. Read and parse frame length.
+
+	switch c.readRemaining {
+	case 126:
+		p, err := c.read(2)
+		if err != nil {
+			return noFrame, err
+		}
+		c.readRemaining = int64(binary.BigEndian.Uint16(p))
+	case 127:
+		p, err := c.read(8)
+		if err != nil {
+			return noFrame, err
+		}
+		c.readRemaining = int64(binary.BigEndian.Uint64(p))
+	}
+
+	// 4. Handle frame masking.
+
+	if mask != c.isServer {
+		return noFrame, c.handleProtocolError("incorrect mask flag")
+	}
+
+	if mask {
+		c.readMaskPos = 0
+		p, err := c.read(len(c.readMaskKey))
+		if err != nil {
+			return noFrame, err
+		}
+		copy(c.readMaskKey[:], p)
+	}
+
+	// 5. For text and binary messages, enforce read limit and return.
+
+	if frameType == continuationFrame || frameType == TextMessage || frameType == BinaryMessage {
+
+		c.readLength += c.readRemaining
+		if c.readLimit > 0 && c.readLength > c.readLimit {
+			c.WriteControl(CloseMessage, FormatCloseMessage(CloseMessageTooBig, ""), time.Now().Add(writeWait))
+			return noFrame, ErrReadLimit
+		}
+
+		return frameType, nil
+	}
+
+	// 6. Read control frame payload.
+
+	var payload []byte
+	if c.readRemaining > 0 {
+		payload, err = c.read(int(c.readRemaining))
+		c.readRemaining = 0
+		if err != nil {
+			return noFrame, err
+		}
+		if c.isServer {
+			maskBytes(c.readMaskKey, 0, payload)
+		}
+	}
+
+	// 7. Process control frame payload.
+
+	switch frameType {
+	case PongMessage:
+		if err := c.handlePong(string(payload)); err != nil {
+			return noFrame, err
+		}
+	case PingMessage:
+		if err := c.handlePing(string(payload)); err != nil {
+			return noFrame, err
+		}
+	case CloseMessage:
+		closeCode := CloseNoStatusReceived
+		closeText := ""
+		if len(payload) >= 2 {
+			closeCode = int(binary.BigEndian.Uint16(payload))
+			if !isValidReceivedCloseCode(closeCode) {
+				return noFrame, c.handleProtocolError("invalid close code")
+			}
+			closeText = string(payload[2:])
+			if !utf8.ValidString(closeText) {
+				return noFrame, c.handleProtocolError("invalid utf8 payload in close frame")
+			}
+		}
+		if err := c.handleClose(closeCode, closeText); err != nil {
+			return noFrame, err
+		}
+		return noFrame, &CloseError{Code: closeCode, Text: closeText}
+	}
+
+	return frameType, nil
+}
+
+func (c *Conn) handleProtocolError(message string) error {
+	c.WriteControl(CloseMessage, FormatCloseMessage(CloseProtocolError, message), time.Now().Add(writeWait))
+	return errors.New("websocket: " + message)
+}
+
+// NextReader returns the next data message received from the peer. The
+// returned messageType is either TextMessage or BinaryMessage.
+//
+// There can be at most one open reader on a connection. NextReader discards
+// the previous message if the application has not already consumed it.
+//
+// Applications must break out of the application's read loop when this method
+// returns a non-nil error value. Errors returned from this method are
+// permanent. Once this method returns a non-nil error, all subsequent calls to
+// this method return the same error.
+func (c *Conn) NextReader() (messageType int, r io.Reader, err error) {
+	// Close previous reader, only relevant for decompression.
+	if c.reader != nil {
+		c.reader.Close()
+		c.reader = nil
+	}
+
+	c.messageReader = nil
+	c.readLength = 0
+
+	for c.readErr == nil {
+		frameType, err := c.advanceFrame()
+		if err != nil {
+			c.readErr = hideTempErr(err)
+			break
+		}
+		if frameType == TextMessage || frameType == BinaryMessage {
+			c.messageReader = &messageReader{c}
+			c.reader = c.messageReader
+			if c.readDecompress {
+				c.reader = c.newDecompressionReader(c.reader)
+			}
+			return frameType, c.reader, nil
+		}
+	}
+
+	// Applications that do handle the error returned from this method spin in
+	// tight loop on connection failure. To help application developers detect
+	// this error, panic on repeated reads to the failed connection.
+	c.readErrCount++
+	if c.readErrCount >= 1000 {
+		panic("repeated read on failed websocket connection")
+	}
+
+	return noFrame, nil, c.readErr
+}
+
+type messageReader struct{ c *Conn }
+
+func (r *messageReader) Read(b []byte) (int, error) {
+	c := r.c
+	if c.messageReader != r {
+		return 0, io.EOF
+	}
+
+	for c.readErr == nil {
+
+		if c.readRemaining > 0 {
+			if int64(len(b)) > c.readRemaining {
+				b = b[:c.readRemaining]
+			}
+			n, err := c.br.Read(b)
+			c.readErr = hideTempErr(err)
+			if c.isServer {
+				c.readMaskPos = maskBytes(c.readMaskKey, c.readMaskPos, b[:n])
+			}
+			c.readRemaining -= int64(n)
+			if c.readRemaining > 0 && c.readErr == io.EOF {
+				c.readErr = errUnexpectedEOF
+			}
+			return n, c.readErr
+		}
+
+		if c.readFinal {
+			c.messageReader = nil
+			return 0, io.EOF
+		}
+
+		frameType, err := c.advanceFrame()
+		switch {
+		case err != nil:
+			c.readErr = hideTempErr(err)
+		case frameType == TextMessage || frameType == BinaryMessage:
+			c.readErr = errors.New("websocket: internal error, unexpected text or binary in Reader")
+		}
+	}
+
+	err := c.readErr
+	if err == io.EOF && c.messageReader == r {
+		err = errUnexpectedEOF
+	}
+	return 0, err
+}
+
+func (r *messageReader) Close() error {
+	return nil
+}
+
+// ReadMessage is a helper method for getting a reader using NextReader and
+// reading from that reader to a buffer.
+func (c *Conn) ReadMessage() (messageType int, p []byte, err error) {
+	var r io.Reader
+	messageType, r, err = c.NextReader()
+	if err != nil {
+		return messageType, nil, err
+	}
+	p, err = ioutil.ReadAll(r)
+	return messageType, p, err
+}
+
+// SetReadDeadline sets the read deadline on the underlying network connection.
+// After a read has timed out, the websocket connection state is corrupt and
+// all future reads will return an error. A zero value for t means reads will
+// not time out.
+func (c *Conn) SetReadDeadline(t time.Time) error {
+	return c.conn.SetReadDeadline(t)
+}
+
+// SetReadLimit sets the maximum size for a message read from the peer. If a
+// message exceeds the limit, the connection sends a close message to the peer
+// and returns ErrReadLimit to the application.
+func (c *Conn) SetReadLimit(limit int64) {
+	c.readLimit = limit
+}
+
+// CloseHandler returns the current close handler
+func (c *Conn) CloseHandler() func(code int, text string) error {
+	return c.handleClose
+}
+
+// SetCloseHandler sets the handler for close messages received from the peer.
+// The code argument to h is the received close code or CloseNoStatusReceived
+// if the close message is empty. The default close handler sends a close
+// message back to the peer.
+//
+// The handler function is called from the NextReader, ReadMessage and message
+// reader Read methods. The application must read the connection to process
+// close messages as described in the section on Control Messages above.
+//
+// The connection read methods return a CloseError when a close message is
+// received. Most applications should handle close messages as part of their
+// normal error handling. Applications should only set a close handler when the
+// application must perform some action before sending a close message back to
+// the peer.
+func (c *Conn) SetCloseHandler(h func(code int, text string) error) {
+	if h == nil {
+		h = func(code int, text string) error {
+			message := FormatCloseMessage(code, "")
+			c.WriteControl(CloseMessage, message, time.Now().Add(writeWait))
+			return nil
+		}
+	}
+	c.handleClose = h
+}
+
+// PingHandler returns the current ping handler
+func (c *Conn) PingHandler() func(appData string) error {
+	return c.handlePing
+}
+
+// SetPingHandler sets the handler for ping messages received from the peer.
+// The appData argument to h is the PING message application data. The default
+// ping handler sends a pong to the peer.
+//
+// The handler function is called from the NextReader, ReadMessage and message
+// reader Read methods. The application must read the connection to process
+// ping messages as described in the section on Control Messages above.
+func (c *Conn) SetPingHandler(h func(appData string) error) {
+	if h == nil {
+		h = func(message string) error {
+			err := c.WriteControl(PongMessage, []byte(message), time.Now().Add(writeWait))
+			if err == ErrCloseSent {
+				return nil
+			} else if e, ok := err.(net.Error); ok && e.Temporary() {
+				return nil
+			}
+			return err
+		}
+	}
+	c.handlePing = h
+}
+
+// PongHandler returns the current pong handler
+func (c *Conn) PongHandler() func(appData string) error {
+	return c.handlePong
+}
+
+// SetPongHandler sets the handler for pong messages received from the peer.
+// The appData argument to h is the PONG message application data. The default
+// pong handler does nothing.
+//
+// The handler function is called from the NextReader, ReadMessage and message
+// reader Read methods. The application must read the connection to process
+// pong messages as described in the section on Control Messages above.
+func (c *Conn) SetPongHandler(h func(appData string) error) {
+	if h == nil {
+		h = func(string) error { return nil }
+	}
+	c.handlePong = h
+}
+
+// UnderlyingConn returns the internal net.Conn. This can be used to further
+// modifications to connection specific flags.
+func (c *Conn) UnderlyingConn() net.Conn {
+	return c.conn
+}
+
+// EnableWriteCompression enables and disables write compression of
+// subsequent text and binary messages. This function is a noop if
+// compression was not negotiated with the peer.
+func (c *Conn) EnableWriteCompression(enable bool) {
+	c.enableWriteCompression = enable
+}
+
+// SetCompressionLevel sets the flate compression level for subsequent text and
+// binary messages. This function is a noop if compression was not negotiated
+// with the peer. See the compress/flate package for a description of
+// compression levels.
+func (c *Conn) SetCompressionLevel(level int) error {
+	if !isValidCompressionLevel(level) {
+		return errors.New("websocket: invalid compression level")
+	}
+	c.compressionLevel = level
+	return nil
+}
+
+// FormatCloseMessage formats closeCode and text as a WebSocket close message.
+// An empty message is returned for code CloseNoStatusReceived.
+func FormatCloseMessage(closeCode int, text string) []byte {
+	if closeCode == CloseNoStatusReceived {
+		// Return empty message because it's illegal to send
+		// CloseNoStatusReceived. Return non-nil value in case application
+		// checks for nil.
+		return []byte{}
+	}
+	buf := make([]byte, 2+len(text))
+	binary.BigEndian.PutUint16(buf, uint16(closeCode))
+	copy(buf[2:], text)
+	return buf
+}
diff --git a/vendor/github.com/gorilla/websocket/conn_write.go b/vendor/github.com/gorilla/websocket/conn_write.go
new file mode 100644
index 0000000..a509a21
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/conn_write.go
@@ -0,0 +1,15 @@
+// Copyright 2016 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build go1.8
+
+package websocket
+
+import "net"
+
+func (c *Conn) writeBufs(bufs ...[]byte) error {
+	b := net.Buffers(bufs)
+	_, err := b.WriteTo(c.conn)
+	return err
+}
diff --git a/vendor/github.com/gorilla/websocket/conn_write_legacy.go b/vendor/github.com/gorilla/websocket/conn_write_legacy.go
new file mode 100644
index 0000000..37edaff
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/conn_write_legacy.go
@@ -0,0 +1,18 @@
+// Copyright 2016 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !go1.8
+
+package websocket
+
+func (c *Conn) writeBufs(bufs ...[]byte) error {
+	for _, buf := range bufs {
+		if len(buf) > 0 {
+			if _, err := c.conn.Write(buf); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
diff --git a/vendor/github.com/gorilla/websocket/doc.go b/vendor/github.com/gorilla/websocket/doc.go
new file mode 100644
index 0000000..dcce1a6
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/doc.go
@@ -0,0 +1,180 @@
+// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package websocket implements the WebSocket protocol defined in RFC 6455.
+//
+// Overview
+//
+// The Conn type represents a WebSocket connection. A server application calls
+// the Upgrader.Upgrade method from an HTTP request handler to get a *Conn:
+//
+//  var upgrader = websocket.Upgrader{
+//      ReadBufferSize:  1024,
+//      WriteBufferSize: 1024,
+//  }
+//
+//  func handler(w http.ResponseWriter, r *http.Request) {
+//      conn, err := upgrader.Upgrade(w, r, nil)
+//      if err != nil {
+//          log.Println(err)
+//          return
+//      }
+//      ... Use conn to send and receive messages.
+//  }
+//
+// Call the connection's WriteMessage and ReadMessage methods to send and
+// receive messages as a slice of bytes. This snippet of code shows how to echo
+// messages using these methods:
+//
+//  for {
+//      messageType, p, err := conn.ReadMessage()
+//      if err != nil {
+//          log.Println(err)
+//          return
+//      }
+//      if err := conn.WriteMessage(messageType, p); err != nil {
+//          log.Println(err)
+//          return
+//      }
+//  }
+//
+// In above snippet of code, p is a []byte and messageType is an int with value
+// websocket.BinaryMessage or websocket.TextMessage.
+//
+// An application can also send and receive messages using the io.WriteCloser
+// and io.Reader interfaces. To send a message, call the connection NextWriter
+// method to get an io.WriteCloser, write the message to the writer and close
+// the writer when done. To receive a message, call the connection NextReader
+// method to get an io.Reader and read until io.EOF is returned. This snippet
+// shows how to echo messages using the NextWriter and NextReader methods:
+//
+//  for {
+//      messageType, r, err := conn.NextReader()
+//      if err != nil {
+//          return
+//      }
+//      w, err := conn.NextWriter(messageType)
+//      if err != nil {
+//          return err
+//      }
+//      if _, err := io.Copy(w, r); err != nil {
+//          return err
+//      }
+//      if err := w.Close(); err != nil {
+//          return err
+//      }
+//  }
+//
+// Data Messages
+//
+// The WebSocket protocol distinguishes between text and binary data messages.
+// Text messages are interpreted as UTF-8 encoded text. The interpretation of
+// binary messages is left to the application.
+//
+// This package uses the TextMessage and BinaryMessage integer constants to
+// identify the two data message types. The ReadMessage and NextReader methods
+// return the type of the received message. The messageType argument to the
+// WriteMessage and NextWriter methods specifies the type of a sent message.
+//
+// It is the application's responsibility to ensure that text messages are
+// valid UTF-8 encoded text.
+//
+// Control Messages
+//
+// The WebSocket protocol defines three types of control messages: close, ping
+// and pong. Call the connection WriteControl, WriteMessage or NextWriter
+// methods to send a control message to the peer.
+//
+// Connections handle received close messages by calling the handler function
+// set with the SetCloseHandler method and by returning a *CloseError from the
+// NextReader, ReadMessage or the message Read method. The default close
+// handler sends a close message to the peer.
+//
+// Connections handle received ping messages by calling the handler function
+// set with the SetPingHandler method. The default ping handler sends a pong
+// message to the peer.
+//
+// Connections handle received pong messages by calling the handler function
+// set with the SetPongHandler method. The default pong handler does nothing.
+// If an application sends ping messages, then the application should set a
+// pong handler to receive the corresponding pong.
+//
+// The control message handler functions are called from the NextReader,
+// ReadMessage and message reader Read methods. The default close and ping
+// handlers can block these methods for a short time when the handler writes to
+// the connection.
+//
+// The application must read the connection to process close, ping and pong
+// messages sent from the peer. If the application is not otherwise interested
+// in messages from the peer, then the application should start a goroutine to
+// read and discard messages from the peer. A simple example is:
+//
+//  func readLoop(c *websocket.Conn) {
+//      for {
+//          if _, _, err := c.NextReader(); err != nil {
+//              c.Close()
+//              break
+//          }
+//      }
+//  }
+//
+// Concurrency
+//
+// Connections support one concurrent reader and one concurrent writer.
+//
+// Applications are responsible for ensuring that no more than one goroutine
+// calls the write methods (NextWriter, SetWriteDeadline, WriteMessage,
+// WriteJSON, EnableWriteCompression, SetCompressionLevel) concurrently and
+// that no more than one goroutine calls the read methods (NextReader,
+// SetReadDeadline, ReadMessage, ReadJSON, SetPongHandler, SetPingHandler)
+// concurrently.
+//
+// The Close and WriteControl methods can be called concurrently with all other
+// methods.
+//
+// Origin Considerations
+//
+// Web browsers allow Javascript applications to open a WebSocket connection to
+// any host. It's up to the server to enforce an origin policy using the Origin
+// request header sent by the browser.
+//
+// The Upgrader calls the function specified in the CheckOrigin field to check
+// the origin. If the CheckOrigin function returns false, then the Upgrade
+// method fails the WebSocket handshake with HTTP status 403.
+//
+// If the CheckOrigin field is nil, then the Upgrader uses a safe default: fail
+// the handshake if the Origin request header is present and the Origin host is
+// not equal to the Host request header.
+//
+// The deprecated package-level Upgrade function does not perform origin
+// checking. The application is responsible for checking the Origin header
+// before calling the Upgrade function.
+//
+// Compression EXPERIMENTAL
+//
+// Per message compression extensions (RFC 7692) are experimentally supported
+// by this package in a limited capacity. Setting the EnableCompression option
+// to true in Dialer or Upgrader will attempt to negotiate per message deflate
+// support.
+//
+//  var upgrader = websocket.Upgrader{
+//      EnableCompression: true,
+//  }
+//
+// If compression was successfully negotiated with the connection's peer, any
+// message received in compressed form will be automatically decompressed.
+// All Read methods will return uncompressed bytes.
+//
+// Per message compression of messages written to a connection can be enabled
+// or disabled by calling the corresponding Conn method:
+//
+//  conn.EnableWriteCompression(false)
+//
+// Currently this package does not support compression with "context takeover".
+// This means that messages must be compressed and decompressed in isolation,
+// without retaining sliding window or dictionary state across messages. For
+// more details refer to RFC 7692.
+//
+// Use of compression is experimental and may result in decreased performance.
+package websocket
diff --git a/vendor/github.com/gorilla/websocket/json.go b/vendor/github.com/gorilla/websocket/json.go
new file mode 100644
index 0000000..dc2c1f6
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/json.go
@@ -0,0 +1,60 @@
+// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"encoding/json"
+	"io"
+)
+
+// WriteJSON writes the JSON encoding of v as a message.
+//
+// Deprecated: Use c.WriteJSON instead.
+func WriteJSON(c *Conn, v interface{}) error {
+	return c.WriteJSON(v)
+}
+
+// WriteJSON writes the JSON encoding of v as a message.
+//
+// See the documentation for encoding/json Marshal for details about the
+// conversion of Go values to JSON.
+func (c *Conn) WriteJSON(v interface{}) error {
+	w, err := c.NextWriter(TextMessage)
+	if err != nil {
+		return err
+	}
+	err1 := json.NewEncoder(w).Encode(v)
+	err2 := w.Close()
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+// ReadJSON reads the next JSON-encoded message from the connection and stores
+// it in the value pointed to by v.
+//
+// Deprecated: Use c.ReadJSON instead.
+func ReadJSON(c *Conn, v interface{}) error {
+	return c.ReadJSON(v)
+}
+
+// ReadJSON reads the next JSON-encoded message from the connection and stores
+// it in the value pointed to by v.
+//
+// See the documentation for the encoding/json Unmarshal function for details
+// about the conversion of JSON to a Go value.
+func (c *Conn) ReadJSON(v interface{}) error {
+	_, r, err := c.NextReader()
+	if err != nil {
+		return err
+	}
+	err = json.NewDecoder(r).Decode(v)
+	if err == io.EOF {
+		// One value is expected in the message.
+		err = io.ErrUnexpectedEOF
+	}
+	return err
+}
diff --git a/vendor/github.com/gorilla/websocket/mask.go b/vendor/github.com/gorilla/websocket/mask.go
new file mode 100644
index 0000000..577fce9
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/mask.go
@@ -0,0 +1,54 @@
+// Copyright 2016 The Gorilla WebSocket Authors. All rights reserved.  Use of
+// this source code is governed by a BSD-style license that can be found in the
+// LICENSE file.
+
+// +build !appengine
+
+package websocket
+
+import "unsafe"
+
+const wordSize = int(unsafe.Sizeof(uintptr(0)))
+
+func maskBytes(key [4]byte, pos int, b []byte) int {
+	// Mask one byte at a time for small buffers.
+	if len(b) < 2*wordSize {
+		for i := range b {
+			b[i] ^= key[pos&3]
+			pos++
+		}
+		return pos & 3
+	}
+
+	// Mask one byte at a time to word boundary.
+	if n := int(uintptr(unsafe.Pointer(&b[0]))) % wordSize; n != 0 {
+		n = wordSize - n
+		for i := range b[:n] {
+			b[i] ^= key[pos&3]
+			pos++
+		}
+		b = b[n:]
+	}
+
+	// Create aligned word size key.
+	var k [wordSize]byte
+	for i := range k {
+		k[i] = key[(pos+i)&3]
+	}
+	kw := *(*uintptr)(unsafe.Pointer(&k))
+
+	// Mask one word at a time.
+	n := (len(b) / wordSize) * wordSize
+	for i := 0; i < n; i += wordSize {
+		*(*uintptr)(unsafe.Pointer(uintptr(unsafe.Pointer(&b[0])) + uintptr(i))) ^= kw
+	}
+
+	// Mask one byte at a time for remaining bytes.
+	b = b[n:]
+	for i := range b {
+		b[i] ^= key[pos&3]
+		pos++
+	}
+
+	return pos & 3
+}
diff --git a/vendor/github.com/gorilla/websocket/mask_safe.go b/vendor/github.com/gorilla/websocket/mask_safe.go
new file mode 100644
index 0000000..2aac060
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/mask_safe.go
@@ -0,0 +1,15 @@
+// Copyright 2016 The Gorilla WebSocket Authors. All rights reserved.  Use of
+// this source code is governed by a BSD-style license that can be found in the
+// LICENSE file.
+
+// +build appengine
+
+package websocket
+
+func maskBytes(key [4]byte, pos int, b []byte) int {
+	for i := range b {
+		b[i] ^= key[pos&3]
+		pos++
+	}
+	return pos & 3
+}
diff --git a/vendor/github.com/gorilla/websocket/prepared.go b/vendor/github.com/gorilla/websocket/prepared.go
new file mode 100644
index 0000000..74ec565
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/prepared.go
@@ -0,0 +1,102 @@
+// Copyright 2017 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"bytes"
+	"net"
+	"sync"
+	"time"
+)
+
+// PreparedMessage caches on the wire representations of a message payload.
+// Use PreparedMessage to efficiently send a message payload to multiple
+// connections. PreparedMessage is especially useful when compression is used
+// because the CPU and memory expensive compression operation can be executed
+// once for a given set of compression options.
+type PreparedMessage struct {
+	messageType int
+	data        []byte
+	mu          sync.Mutex
+	frames      map[prepareKey]*preparedFrame
+}
+
+// prepareKey defines a unique set of options to cache prepared frames in PreparedMessage.
+type prepareKey struct {
+	isServer         bool
+	compress         bool
+	compressionLevel int
+}
+
+// preparedFrame contains data in wire representation.
+type preparedFrame struct {
+	once sync.Once
+	data []byte
+}
+
+// NewPreparedMessage returns an initialized PreparedMessage. You can then send
+// it to connection using WritePreparedMessage method. Valid wire
+// representation will be calculated lazily only once for a set of current
+// connection options.
+func NewPreparedMessage(messageType int, data []byte) (*PreparedMessage, error) {
+	pm := &PreparedMessage{
+		messageType: messageType,
+		frames:      make(map[prepareKey]*preparedFrame),
+		data:        data,
+	}
+
+	// Prepare a plain server frame.
+	_, frameData, err := pm.frame(prepareKey{isServer: true, compress: false})
+	if err != nil {
+		return nil, err
+	}
+
+	// To protect against caller modifying the data argument, remember the data
+	// copied to the plain server frame.
+	pm.data = frameData[len(frameData)-len(data):]
+	return pm, nil
+}
+
+func (pm *PreparedMessage) frame(key prepareKey) (int, []byte, error) {
+	pm.mu.Lock()
+	frame, ok := pm.frames[key]
+	if !ok {
+		frame = &preparedFrame{}
+		pm.frames[key] = frame
+	}
+	pm.mu.Unlock()
+
+	var err error
+	frame.once.Do(func() {
+		// Prepare a frame using a 'fake' connection.
+		// TODO: Refactor code in conn.go to allow more direct construction of
+		// the frame.
+		mu := make(chan bool, 1)
+		mu <- true
+		var nc prepareConn
+		c := &Conn{
+			conn:                   &nc,
+			mu:                     mu,
+			isServer:               key.isServer,
+			compressionLevel:       key.compressionLevel,
+			enableWriteCompression: true,
+			writeBuf:               make([]byte, defaultWriteBufferSize+maxFrameHeaderSize),
+		}
+		if key.compress {
+			c.newCompressionWriter = compressNoContextTakeover
+		}
+		err = c.WriteMessage(pm.messageType, pm.data)
+		frame.data = nc.buf.Bytes()
+	})
+	return pm.messageType, frame.data, err
+}
+
+type prepareConn struct {
+	buf bytes.Buffer
+	net.Conn
+}
+
+func (pc *prepareConn) Write(p []byte) (int, error)        { return pc.buf.Write(p) }
+func (pc *prepareConn) SetWriteDeadline(t time.Time) error { return nil }
diff --git a/vendor/github.com/gorilla/websocket/proxy.go b/vendor/github.com/gorilla/websocket/proxy.go
new file mode 100644
index 0000000..bf2478e
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/proxy.go
@@ -0,0 +1,77 @@
+// Copyright 2017 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"bufio"
+	"encoding/base64"
+	"errors"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+type netDialerFunc func(network, addr string) (net.Conn, error)
+
+func (fn netDialerFunc) Dial(network, addr string) (net.Conn, error) {
+	return fn(network, addr)
+}
+
+func init() {
+	proxy_RegisterDialerType("http", func(proxyURL *url.URL, forwardDialer proxy_Dialer) (proxy_Dialer, error) {
+		return &httpProxyDialer{proxyURL: proxyURL, fowardDial: forwardDialer.Dial}, nil
+	})
+}
+
+type httpProxyDialer struct {
+	proxyURL   *url.URL
+	fowardDial func(network, addr string) (net.Conn, error)
+}
+
+func (hpd *httpProxyDialer) Dial(network string, addr string) (net.Conn, error) {
+	hostPort, _ := hostPortNoPort(hpd.proxyURL)
+	conn, err := hpd.fowardDial(network, hostPort)
+	if err != nil {
+		return nil, err
+	}
+
+	connectHeader := make(http.Header)
+	if user := hpd.proxyURL.User; user != nil {
+		proxyUser := user.Username()
+		if proxyPassword, passwordSet := user.Password(); passwordSet {
+			credential := base64.StdEncoding.EncodeToString([]byte(proxyUser + ":" + proxyPassword))
+			connectHeader.Set("Proxy-Authorization", "Basic "+credential)
+		}
+	}
+
+	connectReq := &http.Request{
+		Method: "CONNECT",
+		URL:    &url.URL{Opaque: addr},
+		Host:   addr,
+		Header: connectHeader,
+	}
+
+	if err := connectReq.Write(conn); err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	// Read response. It's OK to use and discard buffered reader here becaue
+	// the remote server does not speak until spoken to.
+	br := bufio.NewReader(conn)
+	resp, err := http.ReadResponse(br, connectReq)
+	if err != nil {
+		conn.Close()
+		return nil, err
+	}
+
+	if resp.StatusCode != 200 {
+		conn.Close()
+		f := strings.SplitN(resp.Status, " ", 2)
+		return nil, errors.New(f[1])
+	}
+	return conn, nil
+}
diff --git a/vendor/github.com/gorilla/websocket/server.go b/vendor/github.com/gorilla/websocket/server.go
new file mode 100644
index 0000000..a761824
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/server.go
@@ -0,0 +1,363 @@
+// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"bufio"
+	"errors"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+// HandshakeError describes an error with the handshake from the peer.
+type HandshakeError struct {
+	message string
+}
+
+func (e HandshakeError) Error() string { return e.message }
+
+// Upgrader specifies parameters for upgrading an HTTP connection to a
+// WebSocket connection.
+type Upgrader struct {
+	// HandshakeTimeout specifies the duration for the handshake to complete.
+	HandshakeTimeout time.Duration
+
+	// ReadBufferSize and WriteBufferSize specify I/O buffer sizes. If a buffer
+	// size is zero, then buffers allocated by the HTTP server are used. The
+	// I/O buffer sizes do not limit the size of the messages that can be sent
+	// or received.
+	ReadBufferSize, WriteBufferSize int
+
+	// WriteBufferPool is a pool of buffers for write operations. If the value
+	// is not set, then write buffers are allocated to the connection for the
+	// lifetime of the connection.
+	//
+	// A pool is most useful when the application has a modest volume of writes
+	// across a large number of connections.
+	//
+	// Applications should use a single pool for each unique value of
+	// WriteBufferSize.
+	WriteBufferPool BufferPool
+
+	// Subprotocols specifies the server's supported protocols in order of
+	// preference. If this field is not nil, then the Upgrade method negotiates a
+	// subprotocol by selecting the first match in this list with a protocol
+	// requested by the client. If there's no match, then no protocol is
+	// negotiated (the Sec-Websocket-Protocol header is not included in the
+	// handshake response).
+	Subprotocols []string
+
+	// Error specifies the function for generating HTTP error responses. If Error
+	// is nil, then http.Error is used to generate the HTTP response.
+	Error func(w http.ResponseWriter, r *http.Request, status int, reason error)
+
+	// CheckOrigin returns true if the request Origin header is acceptable. If
+	// CheckOrigin is nil, then a safe default is used: return false if the
+	// Origin request header is present and the origin host is not equal to
+	// request Host header.
+	//
+	// A CheckOrigin function should carefully validate the request origin to
+	// prevent cross-site request forgery.
+	CheckOrigin func(r *http.Request) bool
+
+	// EnableCompression specify if the server should attempt to negotiate per
+	// message compression (RFC 7692). Setting this value to true does not
+	// guarantee that compression will be supported. Currently only "no context
+	// takeover" modes are supported.
+	EnableCompression bool
+}
+
+func (u *Upgrader) returnError(w http.ResponseWriter, r *http.Request, status int, reason string) (*Conn, error) {
+	err := HandshakeError{reason}
+	if u.Error != nil {
+		u.Error(w, r, status, err)
+	} else {
+		w.Header().Set("Sec-Websocket-Version", "13")
+		http.Error(w, http.StatusText(status), status)
+	}
+	return nil, err
+}
+
+// checkSameOrigin returns true if the origin is not set or is equal to the request host.
+func checkSameOrigin(r *http.Request) bool {
+	origin := r.Header["Origin"]
+	if len(origin) == 0 {
+		return true
+	}
+	u, err := url.Parse(origin[0])
+	if err != nil {
+		return false
+	}
+	return equalASCIIFold(u.Host, r.Host)
+}
+
+func (u *Upgrader) selectSubprotocol(r *http.Request, responseHeader http.Header) string {
+	if u.Subprotocols != nil {
+		clientProtocols := Subprotocols(r)
+		for _, serverProtocol := range u.Subprotocols {
+			for _, clientProtocol := range clientProtocols {
+				if clientProtocol == serverProtocol {
+					return clientProtocol
+				}
+			}
+		}
+	} else if responseHeader != nil {
+		return responseHeader.Get("Sec-Websocket-Protocol")
+	}
+	return ""
+}
+
+// Upgrade upgrades the HTTP server connection to the WebSocket protocol.
+//
+// The responseHeader is included in the response to the client's upgrade
+// request. Use the responseHeader to specify cookies (Set-Cookie) and the
+// application negotiated subprotocol (Sec-WebSocket-Protocol).
+//
+// If the upgrade fails, then Upgrade replies to the client with an HTTP error
+// response.
+func (u *Upgrader) Upgrade(w http.ResponseWriter, r *http.Request, responseHeader http.Header) (*Conn, error) {
+	const badHandshake = "websocket: the client is not using the websocket protocol: "
+
+	if !tokenListContainsValue(r.Header, "Connection", "upgrade") {
+		return u.returnError(w, r, http.StatusBadRequest, badHandshake+"'upgrade' token not found in 'Connection' header")
+	}
+
+	if !tokenListContainsValue(r.Header, "Upgrade", "websocket") {
+		return u.returnError(w, r, http.StatusBadRequest, badHandshake+"'websocket' token not found in 'Upgrade' header")
+	}
+
+	if r.Method != "GET" {
+		return u.returnError(w, r, http.StatusMethodNotAllowed, badHandshake+"request method is not GET")
+	}
+
+	if !tokenListContainsValue(r.Header, "Sec-Websocket-Version", "13") {
+		return u.returnError(w, r, http.StatusBadRequest, "websocket: unsupported version: 13 not found in 'Sec-Websocket-Version' header")
+	}
+
+	if _, ok := responseHeader["Sec-Websocket-Extensions"]; ok {
+		return u.returnError(w, r, http.StatusInternalServerError, "websocket: application specific 'Sec-WebSocket-Extensions' headers are unsupported")
+	}
+
+	checkOrigin := u.CheckOrigin
+	if checkOrigin == nil {
+		checkOrigin = checkSameOrigin
+	}
+	if !checkOrigin(r) {
+		return u.returnError(w, r, http.StatusForbidden, "websocket: request origin not allowed by Upgrader.CheckOrigin")
+	}
+
+	challengeKey := r.Header.Get("Sec-Websocket-Key")
+	if challengeKey == "" {
+		return u.returnError(w, r, http.StatusBadRequest, "websocket: not a websocket handshake: `Sec-WebSocket-Key' header is missing or blank")
+	}
+
+	subprotocol := u.selectSubprotocol(r, responseHeader)
+
+	// Negotiate PMCE
+	var compress bool
+	if u.EnableCompression {
+		for _, ext := range parseExtensions(r.Header) {
+			if ext[""] != "permessage-deflate" {
+				continue
+			}
+			compress = true
+			break
+		}
+	}
+
+	h, ok := w.(http.Hijacker)
+	if !ok {
+		return u.returnError(w, r, http.StatusInternalServerError, "websocket: response does not implement http.Hijacker")
+	}
+	var brw *bufio.ReadWriter
+	netConn, brw, err := h.Hijack()
+	if err != nil {
+		return u.returnError(w, r, http.StatusInternalServerError, err.Error())
+	}
+
+	if brw.Reader.Buffered() > 0 {
+		netConn.Close()
+		return nil, errors.New("websocket: client sent data before handshake is complete")
+	}
+
+	var br *bufio.Reader
+	if u.ReadBufferSize == 0 && bufioReaderSize(netConn, brw.Reader) > 256 {
+		// Reuse hijacked buffered reader as connection reader.
+		br = brw.Reader
+	}
+
+	buf := bufioWriterBuffer(netConn, brw.Writer)
+
+	var writeBuf []byte
+	if u.WriteBufferPool == nil && u.WriteBufferSize == 0 && len(buf) >= maxFrameHeaderSize+256 {
+		// Reuse hijacked write buffer as connection buffer.
+		writeBuf = buf
+	}
+
+	c := newConn(netConn, true, u.ReadBufferSize, u.WriteBufferSize, u.WriteBufferPool, br, writeBuf)
+	c.subprotocol = subprotocol
+
+	if compress {
+		c.newCompressionWriter = compressNoContextTakeover
+		c.newDecompressionReader = decompressNoContextTakeover
+	}
+
+	// Use larger of hijacked buffer and connection write buffer for header.
+	p := buf
+	if len(c.writeBuf) > len(p) {
+		p = c.writeBuf
+	}
+	p = p[:0]
+
+	p = append(p, "HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: "...)
+	p = append(p, computeAcceptKey(challengeKey)...)
+	p = append(p, "\r\n"...)
+	if c.subprotocol != "" {
+		p = append(p, "Sec-WebSocket-Protocol: "...)
+		p = append(p, c.subprotocol...)
+		p = append(p, "\r\n"...)
+	}
+	if compress {
+		p = append(p, "Sec-WebSocket-Extensions: permessage-deflate; server_no_context_takeover; client_no_context_takeover\r\n"...)
+	}
+	for k, vs := range responseHeader {
+		if k == "Sec-Websocket-Protocol" {
+			continue
+		}
+		for _, v := range vs {
+			p = append(p, k...)
+			p = append(p, ": "...)
+			for i := 0; i < len(v); i++ {
+				b := v[i]
+				if b <= 31 {
+					// prevent response splitting.
+					b = ' '
+				}
+				p = append(p, b)
+			}
+			p = append(p, "\r\n"...)
+		}
+	}
+	p = append(p, "\r\n"...)
+
+	// Clear deadlines set by HTTP server.
+	netConn.SetDeadline(time.Time{})
+
+	if u.HandshakeTimeout > 0 {
+		netConn.SetWriteDeadline(time.Now().Add(u.HandshakeTimeout))
+	}
+	if _, err = netConn.Write(p); err != nil {
+		netConn.Close()
+		return nil, err
+	}
+	if u.HandshakeTimeout > 0 {
+		netConn.SetWriteDeadline(time.Time{})
+	}
+
+	return c, nil
+}
+
+// Upgrade upgrades the HTTP server connection to the WebSocket protocol.
+//
+// Deprecated: Use websocket.Upgrader instead.
+//
+// Upgrade does not perform origin checking. The application is responsible for
+// checking the Origin header before calling Upgrade. An example implementation
+// of the same origin policy check is:
+//
+//	if req.Header.Get("Origin") != "http://"+req.Host {
+//		http.Error(w, "Origin not allowed", http.StatusForbidden)
+//		return
+//	}
+//
+// If the endpoint supports subprotocols, then the application is responsible
+// for negotiating the protocol used on the connection. Use the Subprotocols()
+// function to get the subprotocols requested by the client. Use the
+// Sec-Websocket-Protocol response header to specify the subprotocol selected
+// by the application.
+//
+// The responseHeader is included in the response to the client's upgrade
+// request. Use the responseHeader to specify cookies (Set-Cookie) and the
+// negotiated subprotocol (Sec-Websocket-Protocol).
+//
+// The connection buffers IO to the underlying network connection. The
+// readBufSize and writeBufSize parameters specify the size of the buffers to
+// use. Messages can be larger than the buffers.
+//
+// If the request is not a valid WebSocket handshake, then Upgrade returns an
+// error of type HandshakeError. Applications should handle this error by
+// replying to the client with an HTTP error response.
+func Upgrade(w http.ResponseWriter, r *http.Request, responseHeader http.Header, readBufSize, writeBufSize int) (*Conn, error) {
+	u := Upgrader{ReadBufferSize: readBufSize, WriteBufferSize: writeBufSize}
+	u.Error = func(w http.ResponseWriter, r *http.Request, status int, reason error) {
+		// don't return errors to maintain backwards compatibility
+	}
+	u.CheckOrigin = func(r *http.Request) bool {
+		// allow all connections by default
+		return true
+	}
+	return u.Upgrade(w, r, responseHeader)
+}
+
+// Subprotocols returns the subprotocols requested by the client in the
+// Sec-Websocket-Protocol header.
+func Subprotocols(r *http.Request) []string {
+	h := strings.TrimSpace(r.Header.Get("Sec-Websocket-Protocol"))
+	if h == "" {
+		return nil
+	}
+	protocols := strings.Split(h, ",")
+	for i := range protocols {
+		protocols[i] = strings.TrimSpace(protocols[i])
+	}
+	return protocols
+}
+
+// IsWebSocketUpgrade returns true if the client requested upgrade to the
+// WebSocket protocol.
+func IsWebSocketUpgrade(r *http.Request) bool {
+	return tokenListContainsValue(r.Header, "Connection", "upgrade") &&
+		tokenListContainsValue(r.Header, "Upgrade", "websocket")
+}
+
+// bufioReaderSize size returns the size of a bufio.Reader.
+func bufioReaderSize(originalReader io.Reader, br *bufio.Reader) int {
+	// This code assumes that peek on a reset reader returns
+	// bufio.Reader.buf[:0].
+	// TODO: Use bufio.Reader.Size() after Go 1.10
+	br.Reset(originalReader)
+	if p, err := br.Peek(0); err == nil {
+		return cap(p)
+	}
+	return 0
+}
+
+// writeHook is an io.Writer that records the last slice passed to it vio
+// io.Writer.Write.
+type writeHook struct {
+	p []byte
+}
+
+func (wh *writeHook) Write(p []byte) (int, error) {
+	wh.p = p
+	return len(p), nil
+}
+
+// bufioWriterBuffer grabs the buffer from a bufio.Writer.
+func bufioWriterBuffer(originalWriter io.Writer, bw *bufio.Writer) []byte {
+	// This code assumes that bufio.Writer.buf[:1] is passed to the
+	// bufio.Writer's underlying writer.
+	var wh writeHook
+	bw.Reset(&wh)
+	bw.WriteByte(0)
+	bw.Flush()
+
+	bw.Reset(originalWriter)
+
+	return wh.p[:cap(wh.p)]
+}
diff --git a/vendor/github.com/gorilla/websocket/trace.go b/vendor/github.com/gorilla/websocket/trace.go
new file mode 100644
index 0000000..834f122
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/trace.go
@@ -0,0 +1,19 @@
+// +build go1.8
+
+package websocket
+
+import (
+	"crypto/tls"
+	"net/http/httptrace"
+)
+
+func doHandshakeWithTrace(trace *httptrace.ClientTrace, tlsConn *tls.Conn, cfg *tls.Config) error {
+	if trace.TLSHandshakeStart != nil {
+		trace.TLSHandshakeStart()
+	}
+	err := doHandshake(tlsConn, cfg)
+	if trace.TLSHandshakeDone != nil {
+		trace.TLSHandshakeDone(tlsConn.ConnectionState(), err)
+	}
+	return err
+}
diff --git a/vendor/github.com/gorilla/websocket/trace_17.go b/vendor/github.com/gorilla/websocket/trace_17.go
new file mode 100644
index 0000000..77d05a0
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/trace_17.go
@@ -0,0 +1,12 @@
+// +build !go1.8
+
+package websocket
+
+import (
+	"crypto/tls"
+	"net/http/httptrace"
+)
+
+func doHandshakeWithTrace(trace *httptrace.ClientTrace, tlsConn *tls.Conn, cfg *tls.Config) error {
+	return doHandshake(tlsConn, cfg)
+}
diff --git a/vendor/github.com/gorilla/websocket/util.go b/vendor/github.com/gorilla/websocket/util.go
new file mode 100644
index 0000000..354001e
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/util.go
@@ -0,0 +1,237 @@
+// Copyright 2013 The Gorilla WebSocket Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package websocket
+
+import (
+	"crypto/rand"
+	"crypto/sha1"
+	"encoding/base64"
+	"io"
+	"net/http"
+	"strings"
+	"unicode/utf8"
+)
+
+var keyGUID = []byte("258EAFA5-E914-47DA-95CA-C5AB0DC85B11")
+
+func computeAcceptKey(challengeKey string) string {
+	h := sha1.New()
+	h.Write([]byte(challengeKey))
+	h.Write(keyGUID)
+	return base64.StdEncoding.EncodeToString(h.Sum(nil))
+}
+
+func generateChallengeKey() (string, error) {
+	p := make([]byte, 16)
+	if _, err := io.ReadFull(rand.Reader, p); err != nil {
+		return "", err
+	}
+	return base64.StdEncoding.EncodeToString(p), nil
+}
+
+// Octet types from RFC 2616.
+var octetTypes [256]byte
+
+const (
+	isTokenOctet = 1 << iota
+	isSpaceOctet
+)
+
+func init() {
+	// From RFC 2616
+	//
+	// OCTET      = <any 8-bit sequence of data>
+	// CHAR       = <any US-ASCII character (octets 0 - 127)>
+	// CTL        = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
+	// CR         = <US-ASCII CR, carriage return (13)>
+	// LF         = <US-ASCII LF, linefeed (10)>
+	// SP         = <US-ASCII SP, space (32)>
+	// HT         = <US-ASCII HT, horizontal-tab (9)>
+	// <">        = <US-ASCII double-quote mark (34)>
+	// CRLF       = CR LF
+	// LWS        = [CRLF] 1*( SP | HT )
+	// TEXT       = <any OCTET except CTLs, but including LWS>
+	// separators = "(" | ")" | "<" | ">" | "@" | "," | ";" | ":" | "\" | <">
+	//              | "/" | "[" | "]" | "?" | "=" | "{" | "}" | SP | HT
+	// token      = 1*<any CHAR except CTLs or separators>
+	// qdtext     = <any TEXT except <">>
+
+	for c := 0; c < 256; c++ {
+		var t byte
+		isCtl := c <= 31 || c == 127
+		isChar := 0 <= c && c <= 127
+		isSeparator := strings.IndexRune(" \t\"(),/:;<=>?@[]\\{}", rune(c)) >= 0
+		if strings.IndexRune(" \t\r\n", rune(c)) >= 0 {
+			t |= isSpaceOctet
+		}
+		if isChar && !isCtl && !isSeparator {
+			t |= isTokenOctet
+		}
+		octetTypes[c] = t
+	}
+}
+
+func skipSpace(s string) (rest string) {
+	i := 0
+	for ; i < len(s); i++ {
+		if octetTypes[s[i]]&isSpaceOctet == 0 {
+			break
+		}
+	}
+	return s[i:]
+}
+
+func nextToken(s string) (token, rest string) {
+	i := 0
+	for ; i < len(s); i++ {
+		if octetTypes[s[i]]&isTokenOctet == 0 {
+			break
+		}
+	}
+	return s[:i], s[i:]
+}
+
+func nextTokenOrQuoted(s string) (value string, rest string) {
+	if !strings.HasPrefix(s, "\"") {
+		return nextToken(s)
+	}
+	s = s[1:]
+	for i := 0; i < len(s); i++ {
+		switch s[i] {
+		case '"':
+			return s[:i], s[i+1:]
+		case '\\':
+			p := make([]byte, len(s)-1)
+			j := copy(p, s[:i])
+			escape := true
+			for i = i + 1; i < len(s); i++ {
+				b := s[i]
+				switch {
+				case escape:
+					escape = false
+					p[j] = b
+					j++
+				case b == '\\':
+					escape = true
+				case b == '"':
+					return string(p[:j]), s[i+1:]
+				default:
+					p[j] = b
+					j++
+				}
+			}
+			return "", ""
+		}
+	}
+	return "", ""
+}
+
+// equalASCIIFold returns true if s is equal to t with ASCII case folding.
+func equalASCIIFold(s, t string) bool {
+	for s != "" && t != "" {
+		sr, size := utf8.DecodeRuneInString(s)
+		s = s[size:]
+		tr, size := utf8.DecodeRuneInString(t)
+		t = t[size:]
+		if sr == tr {
+			continue
+		}
+		if 'A' <= sr && sr <= 'Z' {
+			sr = sr + 'a' - 'A'
+		}
+		if 'A' <= tr && tr <= 'Z' {
+			tr = tr + 'a' - 'A'
+		}
+		if sr != tr {
+			return false
+		}
+	}
+	return s == t
+}
+
+// tokenListContainsValue returns true if the 1#token header with the given
+// name contains a token equal to value with ASCII case folding.
+func tokenListContainsValue(header http.Header, name string, value string) bool {
+headers:
+	for _, s := range header[name] {
+		for {
+			var t string
+			t, s = nextToken(skipSpace(s))
+			if t == "" {
+				continue headers
+			}
+			s = skipSpace(s)
+			if s != "" && s[0] != ',' {
+				continue headers
+			}
+			if equalASCIIFold(t, value) {
+				return true
+			}
+			if s == "" {
+				continue headers
+			}
+			s = s[1:]
+		}
+	}
+	return false
+}
+
+// parseExtensions parses WebSocket extensions from a header.
+func parseExtensions(header http.Header) []map[string]string {
+	// From RFC 6455:
+	//
+	//  Sec-WebSocket-Extensions = extension-list
+	//  extension-list = 1#extension
+	//  extension = extension-token *( ";" extension-param )
+	//  extension-token = registered-token
+	//  registered-token = token
+	//  extension-param = token [ "=" (token | quoted-string) ]
+	//     ;When using the quoted-string syntax variant, the value
+	//     ;after quoted-string unescaping MUST conform to the
+	//     ;'token' ABNF.
+
+	var result []map[string]string
+headers:
+	for _, s := range header["Sec-Websocket-Extensions"] {
+		for {
+			var t string
+			t, s = nextToken(skipSpace(s))
+			if t == "" {
+				continue headers
+			}
+			ext := map[string]string{"": t}
+			for {
+				s = skipSpace(s)
+				if !strings.HasPrefix(s, ";") {
+					break
+				}
+				var k string
+				k, s = nextToken(skipSpace(s[1:]))
+				if k == "" {
+					continue headers
+				}
+				s = skipSpace(s)
+				var v string
+				if strings.HasPrefix(s, "=") {
+					v, s = nextTokenOrQuoted(skipSpace(s[1:]))
+					s = skipSpace(s)
+				}
+				if s != "" && s[0] != ',' && s[0] != ';' {
+					continue headers
+				}
+				ext[k] = v
+			}
+			if s != "" && s[0] != ',' {
+				continue headers
+			}
+			result = append(result, ext)
+			if s == "" {
+				continue headers
+			}
+			s = s[1:]
+		}
+	}
+	return result
+}
diff --git a/vendor/github.com/gorilla/websocket/x_net_proxy.go b/vendor/github.com/gorilla/websocket/x_net_proxy.go
new file mode 100644
index 0000000..2e668f6
--- /dev/null
+++ b/vendor/github.com/gorilla/websocket/x_net_proxy.go
@@ -0,0 +1,473 @@
+// Code generated by golang.org/x/tools/cmd/bundle. DO NOT EDIT.
+//go:generate bundle -o x_net_proxy.go golang.org/x/net/proxy
+
+// Package proxy provides support for a variety of protocols to proxy network
+// data.
+//
+
+package websocket
+
+import (
+	"errors"
+	"io"
+	"net"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+type proxy_direct struct{}
+
+// Direct is a direct proxy: one that makes network connections directly.
+var proxy_Direct = proxy_direct{}
+
+func (proxy_direct) Dial(network, addr string) (net.Conn, error) {
+	return net.Dial(network, addr)
+}
+
+// A PerHost directs connections to a default Dialer unless the host name
+// requested matches one of a number of exceptions.
+type proxy_PerHost struct {
+	def, bypass proxy_Dialer
+
+	bypassNetworks []*net.IPNet
+	bypassIPs      []net.IP
+	bypassZones    []string
+	bypassHosts    []string
+}
+
+// NewPerHost returns a PerHost Dialer that directs connections to either
+// defaultDialer or bypass, depending on whether the connection matches one of
+// the configured rules.
+func proxy_NewPerHost(defaultDialer, bypass proxy_Dialer) *proxy_PerHost {
+	return &proxy_PerHost{
+		def:    defaultDialer,
+		bypass: bypass,
+	}
+}
+
+// Dial connects to the address addr on the given network through either
+// defaultDialer or bypass.
+func (p *proxy_PerHost) Dial(network, addr string) (c net.Conn, err error) {
+	host, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		return nil, err
+	}
+
+	return p.dialerForRequest(host).Dial(network, addr)
+}
+
+func (p *proxy_PerHost) dialerForRequest(host string) proxy_Dialer {
+	if ip := net.ParseIP(host); ip != nil {
+		for _, net := range p.bypassNetworks {
+			if net.Contains(ip) {
+				return p.bypass
+			}
+		}
+		for _, bypassIP := range p.bypassIPs {
+			if bypassIP.Equal(ip) {
+				return p.bypass
+			}
+		}
+		return p.def
+	}
+
+	for _, zone := range p.bypassZones {
+		if strings.HasSuffix(host, zone) {
+			return p.bypass
+		}
+		if host == zone[1:] {
+			// For a zone ".example.com", we match "example.com"
+			// too.
+			return p.bypass
+		}
+	}
+	for _, bypassHost := range p.bypassHosts {
+		if bypassHost == host {
+			return p.bypass
+		}
+	}
+	return p.def
+}
+
+// AddFromString parses a string that contains comma-separated values
+// specifying hosts that should use the bypass proxy. Each value is either an
+// IP address, a CIDR range, a zone (*.example.com) or a host name
+// (localhost). A best effort is made to parse the string and errors are
+// ignored.
+func (p *proxy_PerHost) AddFromString(s string) {
+	hosts := strings.Split(s, ",")
+	for _, host := range hosts {
+		host = strings.TrimSpace(host)
+		if len(host) == 0 {
+			continue
+		}
+		if strings.Contains(host, "/") {
+			// We assume that it's a CIDR address like 127.0.0.0/8
+			if _, net, err := net.ParseCIDR(host); err == nil {
+				p.AddNetwork(net)
+			}
+			continue
+		}
+		if ip := net.ParseIP(host); ip != nil {
+			p.AddIP(ip)
+			continue
+		}
+		if strings.HasPrefix(host, "*.") {
+			p.AddZone(host[1:])
+			continue
+		}
+		p.AddHost(host)
+	}
+}
+
+// AddIP specifies an IP address that will use the bypass proxy. Note that
+// this will only take effect if a literal IP address is dialed. A connection
+// to a named host will never match an IP.
+func (p *proxy_PerHost) AddIP(ip net.IP) {
+	p.bypassIPs = append(p.bypassIPs, ip)
+}
+
+// AddNetwork specifies an IP range that will use the bypass proxy. Note that
+// this will only take effect if a literal IP address is dialed. A connection
+// to a named host will never match.
+func (p *proxy_PerHost) AddNetwork(net *net.IPNet) {
+	p.bypassNetworks = append(p.bypassNetworks, net)
+}
+
+// AddZone specifies a DNS suffix that will use the bypass proxy. A zone of
+// "example.com" matches "example.com" and all of its subdomains.
+func (p *proxy_PerHost) AddZone(zone string) {
+	if strings.HasSuffix(zone, ".") {
+		zone = zone[:len(zone)-1]
+	}
+	if !strings.HasPrefix(zone, ".") {
+		zone = "." + zone
+	}
+	p.bypassZones = append(p.bypassZones, zone)
+}
+
+// AddHost specifies a host name that will use the bypass proxy.
+func (p *proxy_PerHost) AddHost(host string) {
+	if strings.HasSuffix(host, ".") {
+		host = host[:len(host)-1]
+	}
+	p.bypassHosts = append(p.bypassHosts, host)
+}
+
+// A Dialer is a means to establish a connection.
+type proxy_Dialer interface {
+	// Dial connects to the given address via the proxy.
+	Dial(network, addr string) (c net.Conn, err error)
+}
+
+// Auth contains authentication parameters that specific Dialers may require.
+type proxy_Auth struct {
+	User, Password string
+}
+
+// FromEnvironment returns the dialer specified by the proxy related variables in
+// the environment.
+func proxy_FromEnvironment() proxy_Dialer {
+	allProxy := proxy_allProxyEnv.Get()
+	if len(allProxy) == 0 {
+		return proxy_Direct
+	}
+
+	proxyURL, err := url.Parse(allProxy)
+	if err != nil {
+		return proxy_Direct
+	}
+	proxy, err := proxy_FromURL(proxyURL, proxy_Direct)
+	if err != nil {
+		return proxy_Direct
+	}
+
+	noProxy := proxy_noProxyEnv.Get()
+	if len(noProxy) == 0 {
+		return proxy
+	}
+
+	perHost := proxy_NewPerHost(proxy, proxy_Direct)
+	perHost.AddFromString(noProxy)
+	return perHost
+}
+
+// proxySchemes is a map from URL schemes to a function that creates a Dialer
+// from a URL with such a scheme.
+var proxy_proxySchemes map[string]func(*url.URL, proxy_Dialer) (proxy_Dialer, error)
+
+// RegisterDialerType takes a URL scheme and a function to generate Dialers from
+// a URL with that scheme and a forwarding Dialer. Registered schemes are used
+// by FromURL.
+func proxy_RegisterDialerType(scheme string, f func(*url.URL, proxy_Dialer) (proxy_Dialer, error)) {
+	if proxy_proxySchemes == nil {
+		proxy_proxySchemes = make(map[string]func(*url.URL, proxy_Dialer) (proxy_Dialer, error))
+	}
+	proxy_proxySchemes[scheme] = f
+}
+
+// FromURL returns a Dialer given a URL specification and an underlying
+// Dialer for it to make network requests.
+func proxy_FromURL(u *url.URL, forward proxy_Dialer) (proxy_Dialer, error) {
+	var auth *proxy_Auth
+	if u.User != nil {
+		auth = new(proxy_Auth)
+		auth.User = u.User.Username()
+		if p, ok := u.User.Password(); ok {
+			auth.Password = p
+		}
+	}
+
+	switch u.Scheme {
+	case "socks5":
+		return proxy_SOCKS5("tcp", u.Host, auth, forward)
+	}
+
+	// If the scheme doesn't match any of the built-in schemes, see if it
+	// was registered by another package.
+	if proxy_proxySchemes != nil {
+		if f, ok := proxy_proxySchemes[u.Scheme]; ok {
+			return f(u, forward)
+		}
+	}
+
+	return nil, errors.New("proxy: unknown scheme: " + u.Scheme)
+}
+
+var (
+	proxy_allProxyEnv = &proxy_envOnce{
+		names: []string{"ALL_PROXY", "all_proxy"},
+	}
+	proxy_noProxyEnv = &proxy_envOnce{
+		names: []string{"NO_PROXY", "no_proxy"},
+	}
+)
+
+// envOnce looks up an environment variable (optionally by multiple
+// names) once. It mitigates expensive lookups on some platforms
+// (e.g. Windows).
+// (Borrowed from net/http/transport.go)
+type proxy_envOnce struct {
+	names []string
+	once  sync.Once
+	val   string
+}
+
+func (e *proxy_envOnce) Get() string {
+	e.once.Do(e.init)
+	return e.val
+}
+
+func (e *proxy_envOnce) init() {
+	for _, n := range e.names {
+		e.val = os.Getenv(n)
+		if e.val != "" {
+			return
+		}
+	}
+}
+
+// SOCKS5 returns a Dialer that makes SOCKSv5 connections to the given address
+// with an optional username and password. See RFC 1928 and RFC 1929.
+func proxy_SOCKS5(network, addr string, auth *proxy_Auth, forward proxy_Dialer) (proxy_Dialer, error) {
+	s := &proxy_socks5{
+		network: network,
+		addr:    addr,
+		forward: forward,
+	}
+	if auth != nil {
+		s.user = auth.User
+		s.password = auth.Password
+	}
+
+	return s, nil
+}
+
+type proxy_socks5 struct {
+	user, password string
+	network, addr  string
+	forward        proxy_Dialer
+}
+
+const proxy_socks5Version = 5
+
+const (
+	proxy_socks5AuthNone     = 0
+	proxy_socks5AuthPassword = 2
+)
+
+const proxy_socks5Connect = 1
+
+const (
+	proxy_socks5IP4    = 1
+	proxy_socks5Domain = 3
+	proxy_socks5IP6    = 4
+)
+
+var proxy_socks5Errors = []string{
+	"",
+	"general failure",
+	"connection forbidden",
+	"network unreachable",
+	"host unreachable",
+	"connection refused",
+	"TTL expired",
+	"command not supported",
+	"address type not supported",
+}
+
+// Dial connects to the address addr on the given network via the SOCKS5 proxy.
+func (s *proxy_socks5) Dial(network, addr string) (net.Conn, error) {
+	switch network {
+	case "tcp", "tcp6", "tcp4":
+	default:
+		return nil, errors.New("proxy: no support for SOCKS5 proxy connections of type " + network)
+	}
+
+	conn, err := s.forward.Dial(s.network, s.addr)
+	if err != nil {
+		return nil, err
+	}
+	if err := s.connect(conn, addr); err != nil {
+		conn.Close()
+		return nil, err
+	}
+	return conn, nil
+}
+
+// connect takes an existing connection to a socks5 proxy server,
+// and commands the server to extend that connection to target,
+// which must be a canonical address with a host and port.
+func (s *proxy_socks5) connect(conn net.Conn, target string) error {
+	host, portStr, err := net.SplitHostPort(target)
+	if err != nil {
+		return err
+	}
+
+	port, err := strconv.Atoi(portStr)
+	if err != nil {
+		return errors.New("proxy: failed to parse port number: " + portStr)
+	}
+	if port < 1 || port > 0xffff {
+		return errors.New("proxy: port number out of range: " + portStr)
+	}
+
+	// the size here is just an estimate
+	buf := make([]byte, 0, 6+len(host))
+
+	buf = append(buf, proxy_socks5Version)
+	if len(s.user) > 0 && len(s.user) < 256 && len(s.password) < 256 {
+		buf = append(buf, 2 /* num auth methods */, proxy_socks5AuthNone, proxy_socks5AuthPassword)
+	} else {
+		buf = append(buf, 1 /* num auth methods */, proxy_socks5AuthNone)
+	}
+
+	if _, err := conn.Write(buf); err != nil {
+		return errors.New("proxy: failed to write greeting to SOCKS5 proxy at " + s.addr + ": " + err.Error())
+	}
+
+	if _, err := io.ReadFull(conn, buf[:2]); err != nil {
+		return errors.New("proxy: failed to read greeting from SOCKS5 proxy at " + s.addr + ": " + err.Error())
+	}
+	if buf[0] != 5 {
+		return errors.New("proxy: SOCKS5 proxy at " + s.addr + " has unexpected version " + strconv.Itoa(int(buf[0])))
+	}
+	if buf[1] == 0xff {
+		return errors.New("proxy: SOCKS5 proxy at " + s.addr + " requires authentication")
+	}
+
+	// See RFC 1929
+	if buf[1] == proxy_socks5AuthPassword {
+		buf = buf[:0]
+		buf = append(buf, 1 /* password protocol version */)
+		buf = append(buf, uint8(len(s.user)))
+		buf = append(buf, s.user...)
+		buf = append(buf, uint8(len(s.password)))
+		buf = append(buf, s.password...)
+
+		if _, err := conn.Write(buf); err != nil {
+			return errors.New("proxy: failed to write authentication request to SOCKS5 proxy at " + s.addr + ": " + err.Error())
+		}
+
+		if _, err := io.ReadFull(conn, buf[:2]); err != nil {
+			return errors.New("proxy: failed to read authentication reply from SOCKS5 proxy at " + s.addr + ": " + err.Error())
+		}
+
+		if buf[1] != 0 {
+			return errors.New("proxy: SOCKS5 proxy at " + s.addr + " rejected username/password")
+		}
+	}
+
+	buf = buf[:0]
+	buf = append(buf, proxy_socks5Version, proxy_socks5Connect, 0 /* reserved */)
+
+	if ip := net.ParseIP(host); ip != nil {
+		if ip4 := ip.To4(); ip4 != nil {
+			buf = append(buf, proxy_socks5IP4)
+			ip = ip4
+		} else {
+			buf = append(buf, proxy_socks5IP6)
+		}
+		buf = append(buf, ip...)
+	} else {
+		if len(host) > 255 {
+			return errors.New("proxy: destination host name too long: " + host)
+		}
+		buf = append(buf, proxy_socks5Domain)
+		buf = append(buf, byte(len(host)))
+		buf = append(buf, host...)
+	}
+	buf = append(buf, byte(port>>8), byte(port))
+
+	if _, err := conn.Write(buf); err != nil {
+		return errors.New("proxy: failed to write connect request to SOCKS5 proxy at " + s.addr + ": " + err.Error())
+	}
+
+	if _, err := io.ReadFull(conn, buf[:4]); err != nil {
+		return errors.New("proxy: failed to read connect reply from SOCKS5 proxy at " + s.addr + ": " + err.Error())
+	}
+
+	failure := "unknown error"
+	if int(buf[1]) < len(proxy_socks5Errors) {
+		failure = proxy_socks5Errors[buf[1]]
+	}
+
+	if len(failure) > 0 {
+		return errors.New("proxy: SOCKS5 proxy at " + s.addr + " failed to connect: " + failure)
+	}
+
+	bytesToDiscard := 0
+	switch buf[3] {
+	case proxy_socks5IP4:
+		bytesToDiscard = net.IPv4len
+	case proxy_socks5IP6:
+		bytesToDiscard = net.IPv6len
+	case proxy_socks5Domain:
+		_, err := io.ReadFull(conn, buf[:1])
+		if err != nil {
+			return errors.New("proxy: failed to read domain length from SOCKS5 proxy at " + s.addr + ": " + err.Error())
+		}
+		bytesToDiscard = int(buf[0])
+	default:
+		return errors.New("proxy: got unknown address type " + strconv.Itoa(int(buf[3])) + " from SOCKS5 proxy at " + s.addr)
+	}
+
+	if cap(buf) < bytesToDiscard {
+		buf = make([]byte, bytesToDiscard)
+	} else {
+		buf = buf[:bytesToDiscard]
+	}
+	if _, err := io.ReadFull(conn, buf); err != nil {
+		return errors.New("proxy: failed to read address from SOCKS5 proxy at " + s.addr + ": " + err.Error())
+	}
+
+	// Also need to discard the port number
+	if _, err := io.ReadFull(conn, buf[:2]); err != nil {
+		return errors.New("proxy: failed to read port from SOCKS5 proxy at " + s.addr + ": " + err.Error())
+	}
+
+	return nil
+}