diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/LICENSE.txt b/vendor/github.com/grpc-ecosystem/grpc-gateway/LICENSE.txt
new file mode 100644
index 0000000..3645162
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/LICENSE.txt
@@ -0,0 +1,27 @@
+Copyright (c) 2015, Gengo, Inc.
+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.
+
+    * Neither the name of Gengo, Inc. nor the names of its
+      contributors may be used to endorse or promote products derived from this
+      software without specific prior written permission.
+
+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 OWNER 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/grpc-ecosystem/grpc-gateway/runtime/BUILD.bazel b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/BUILD.bazel
new file mode 100644
index 0000000..9fce044
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/BUILD.bazel
@@ -0,0 +1,83 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+package(default_visibility = ["//visibility:public"])
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "context.go",
+        "convert.go",
+        "doc.go",
+        "errors.go",
+        "handler.go",
+        "marshal_json.go",
+        "marshal_jsonpb.go",
+        "marshal_proto.go",
+        "marshaler.go",
+        "marshaler_registry.go",
+        "mux.go",
+        "pattern.go",
+        "proto2_convert.go",
+        "proto_errors.go",
+        "query.go",
+    ],
+    importpath = "github.com/grpc-ecosystem/grpc-gateway/runtime",
+    deps = [
+        "//runtime/internal:go_default_library",
+        "//utilities:go_default_library",
+        "@com_github_golang_protobuf//jsonpb:go_default_library",
+        "@com_github_golang_protobuf//proto:go_default_library",
+        "@com_github_golang_protobuf//ptypes:go_default_library",
+        "@com_github_golang_protobuf//ptypes/any:go_default_library",
+        "@com_github_golang_protobuf//ptypes/duration:go_default_library",
+        "@com_github_golang_protobuf//ptypes/timestamp:go_default_library",
+        "@org_golang_google_grpc//codes:go_default_library",
+        "@org_golang_google_grpc//grpclog:go_default_library",
+        "@org_golang_google_grpc//metadata:go_default_library",
+        "@org_golang_google_grpc//status:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    size = "small",
+    srcs = ["pattern_test.go"],
+    embed = [":go_default_library"],
+    deps = ["//utilities:go_default_library"],
+)
+
+go_test(
+    name = "go_default_xtest",
+    size = "small",
+    srcs = [
+        "context_test.go",
+        "errors_test.go",
+        "handler_test.go",
+        "marshal_json_test.go",
+        "marshal_jsonpb_test.go",
+        "marshal_proto_test.go",
+        "marshaler_registry_test.go",
+        "mux_test.go",
+        "query_test.go",
+    ],
+    deps = [
+        ":go_default_library",
+        "//examples/proto/examplepb:go_default_library",
+        "//runtime/internal:go_default_library",
+        "//utilities:go_default_library",
+        "@com_github_golang_protobuf//jsonpb:go_default_library",
+        "@com_github_golang_protobuf//proto:go_default_library",
+        "@com_github_golang_protobuf//ptypes:go_default_library",
+        "@com_github_golang_protobuf//ptypes/duration:go_default_library",
+        "@com_github_golang_protobuf//ptypes/empty:go_default_library",
+        "@com_github_golang_protobuf//ptypes/struct:go_default_library",
+        "@com_github_golang_protobuf//ptypes/timestamp:go_default_library",
+        "@com_github_golang_protobuf//ptypes/wrappers:go_default_library",
+        "@org_golang_google_genproto//protobuf/field_mask:go_default_library",
+        "@org_golang_google_genproto//googleapis/rpc/errdetails:go_default_library",
+        "@org_golang_google_grpc//:go_default_library",
+        "@org_golang_google_grpc//codes:go_default_library",
+        "@org_golang_google_grpc//metadata:go_default_library",
+        "@org_golang_google_grpc//status:go_default_library",
+    ],
+)
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/context.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/context.go
new file mode 100644
index 0000000..896057e
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/context.go
@@ -0,0 +1,210 @@
+package runtime
+
+import (
+	"context"
+	"encoding/base64"
+	"fmt"
+	"net"
+	"net/http"
+	"net/textproto"
+	"strconv"
+	"strings"
+	"time"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+// MetadataHeaderPrefix is the http prefix that represents custom metadata
+// parameters to or from a gRPC call.
+const MetadataHeaderPrefix = "Grpc-Metadata-"
+
+// MetadataPrefix is prepended to permanent HTTP header keys (as specified
+// by the IANA) when added to the gRPC context.
+const MetadataPrefix = "grpcgateway-"
+
+// MetadataTrailerPrefix is prepended to gRPC metadata as it is converted to
+// HTTP headers in a response handled by grpc-gateway
+const MetadataTrailerPrefix = "Grpc-Trailer-"
+
+const metadataGrpcTimeout = "Grpc-Timeout"
+const metadataHeaderBinarySuffix = "-Bin"
+
+const xForwardedFor = "X-Forwarded-For"
+const xForwardedHost = "X-Forwarded-Host"
+
+var (
+	// DefaultContextTimeout is used for gRPC call context.WithTimeout whenever a Grpc-Timeout inbound
+	// header isn't present. If the value is 0 the sent `context` will not have a timeout.
+	DefaultContextTimeout = 0 * time.Second
+)
+
+func decodeBinHeader(v string) ([]byte, error) {
+	if len(v)%4 == 0 {
+		// Input was padded, or padding was not necessary.
+		return base64.StdEncoding.DecodeString(v)
+	}
+	return base64.RawStdEncoding.DecodeString(v)
+}
+
+/*
+AnnotateContext adds context information such as metadata from the request.
+
+At a minimum, the RemoteAddr is included in the fashion of "X-Forwarded-For",
+except that the forwarded destination is not another HTTP service but rather
+a gRPC service.
+*/
+func AnnotateContext(ctx context.Context, mux *ServeMux, req *http.Request) (context.Context, error) {
+	var pairs []string
+	timeout := DefaultContextTimeout
+	if tm := req.Header.Get(metadataGrpcTimeout); tm != "" {
+		var err error
+		timeout, err = timeoutDecode(tm)
+		if err != nil {
+			return nil, status.Errorf(codes.InvalidArgument, "invalid grpc-timeout: %s", tm)
+		}
+	}
+
+	for key, vals := range req.Header {
+		for _, val := range vals {
+			key = textproto.CanonicalMIMEHeaderKey(key)
+			// For backwards-compatibility, pass through 'authorization' header with no prefix.
+			if key == "Authorization" {
+				pairs = append(pairs, "authorization", val)
+			}
+			if h, ok := mux.incomingHeaderMatcher(key); ok {
+				// Handles "-bin" metadata in grpc, since grpc will do another base64
+				// encode before sending to server, we need to decode it first.
+				if strings.HasSuffix(key, metadataHeaderBinarySuffix) {
+					b, err := decodeBinHeader(val)
+					if err != nil {
+						return nil, status.Errorf(codes.InvalidArgument, "invalid binary header %s: %s", key, err)
+					}
+
+					val = string(b)
+				}
+				pairs = append(pairs, h, val)
+			}
+		}
+	}
+	if host := req.Header.Get(xForwardedHost); host != "" {
+		pairs = append(pairs, strings.ToLower(xForwardedHost), host)
+	} else if req.Host != "" {
+		pairs = append(pairs, strings.ToLower(xForwardedHost), req.Host)
+	}
+
+	if addr := req.RemoteAddr; addr != "" {
+		if remoteIP, _, err := net.SplitHostPort(addr); err == nil {
+			if fwd := req.Header.Get(xForwardedFor); fwd == "" {
+				pairs = append(pairs, strings.ToLower(xForwardedFor), remoteIP)
+			} else {
+				pairs = append(pairs, strings.ToLower(xForwardedFor), fmt.Sprintf("%s, %s", fwd, remoteIP))
+			}
+		} else {
+			grpclog.Infof("invalid remote addr: %s", addr)
+		}
+	}
+
+	if timeout != 0 {
+		ctx, _ = context.WithTimeout(ctx, timeout)
+	}
+	if len(pairs) == 0 {
+		return ctx, nil
+	}
+	md := metadata.Pairs(pairs...)
+	for _, mda := range mux.metadataAnnotators {
+		md = metadata.Join(md, mda(ctx, req))
+	}
+	return metadata.NewOutgoingContext(ctx, md), nil
+}
+
+// ServerMetadata consists of metadata sent from gRPC server.
+type ServerMetadata struct {
+	HeaderMD  metadata.MD
+	TrailerMD metadata.MD
+}
+
+type serverMetadataKey struct{}
+
+// NewServerMetadataContext creates a new context with ServerMetadata
+func NewServerMetadataContext(ctx context.Context, md ServerMetadata) context.Context {
+	return context.WithValue(ctx, serverMetadataKey{}, md)
+}
+
+// ServerMetadataFromContext returns the ServerMetadata in ctx
+func ServerMetadataFromContext(ctx context.Context) (md ServerMetadata, ok bool) {
+	md, ok = ctx.Value(serverMetadataKey{}).(ServerMetadata)
+	return
+}
+
+func timeoutDecode(s string) (time.Duration, error) {
+	size := len(s)
+	if size < 2 {
+		return 0, fmt.Errorf("timeout string is too short: %q", s)
+	}
+	d, ok := timeoutUnitToDuration(s[size-1])
+	if !ok {
+		return 0, fmt.Errorf("timeout unit is not recognized: %q", s)
+	}
+	t, err := strconv.ParseInt(s[:size-1], 10, 64)
+	if err != nil {
+		return 0, err
+	}
+	return d * time.Duration(t), nil
+}
+
+func timeoutUnitToDuration(u uint8) (d time.Duration, ok bool) {
+	switch u {
+	case 'H':
+		return time.Hour, true
+	case 'M':
+		return time.Minute, true
+	case 'S':
+		return time.Second, true
+	case 'm':
+		return time.Millisecond, true
+	case 'u':
+		return time.Microsecond, true
+	case 'n':
+		return time.Nanosecond, true
+	default:
+	}
+	return
+}
+
+// isPermanentHTTPHeader checks whether hdr belongs to the list of
+// permenant request headers maintained by IANA.
+// http://www.iana.org/assignments/message-headers/message-headers.xml
+func isPermanentHTTPHeader(hdr string) bool {
+	switch hdr {
+	case
+		"Accept",
+		"Accept-Charset",
+		"Accept-Language",
+		"Accept-Ranges",
+		"Authorization",
+		"Cache-Control",
+		"Content-Type",
+		"Cookie",
+		"Date",
+		"Expect",
+		"From",
+		"Host",
+		"If-Match",
+		"If-Modified-Since",
+		"If-None-Match",
+		"If-Schedule-Tag-Match",
+		"If-Unmodified-Since",
+		"Max-Forwards",
+		"Origin",
+		"Pragma",
+		"Referer",
+		"User-Agent",
+		"Via",
+		"Warning":
+		return true
+	}
+	return false
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/convert.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/convert.go
new file mode 100644
index 0000000..bd54ba1
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/convert.go
@@ -0,0 +1,254 @@
+package runtime
+
+import (
+	"encoding/base64"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/golang/protobuf/jsonpb"
+	"github.com/golang/protobuf/ptypes/duration"
+	"github.com/golang/protobuf/ptypes/timestamp"
+)
+
+// String just returns the given string.
+// It is just for compatibility to other types.
+func String(val string) (string, error) {
+	return val, nil
+}
+
+// StringSlice converts 'val' where individual strings are separated by
+// 'sep' into a string slice.
+func StringSlice(val, sep string) ([]string, error) {
+	return strings.Split(val, sep), nil
+}
+
+// Bool converts the given string representation of a boolean value into bool.
+func Bool(val string) (bool, error) {
+	return strconv.ParseBool(val)
+}
+
+// BoolSlice converts 'val' where individual booleans are separated by
+// 'sep' into a bool slice.
+func BoolSlice(val, sep string) ([]bool, error) {
+	s := strings.Split(val, sep)
+	values := make([]bool, len(s))
+	for i, v := range s {
+		value, err := Bool(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Float64 converts the given string representation into representation of a floating point number into float64.
+func Float64(val string) (float64, error) {
+	return strconv.ParseFloat(val, 64)
+}
+
+// Float64Slice converts 'val' where individual floating point numbers are separated by
+// 'sep' into a float64 slice.
+func Float64Slice(val, sep string) ([]float64, error) {
+	s := strings.Split(val, sep)
+	values := make([]float64, len(s))
+	for i, v := range s {
+		value, err := Float64(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Float32 converts the given string representation of a floating point number into float32.
+func Float32(val string) (float32, error) {
+	f, err := strconv.ParseFloat(val, 32)
+	if err != nil {
+		return 0, err
+	}
+	return float32(f), nil
+}
+
+// Float32Slice converts 'val' where individual floating point numbers are separated by
+// 'sep' into a float32 slice.
+func Float32Slice(val, sep string) ([]float32, error) {
+	s := strings.Split(val, sep)
+	values := make([]float32, len(s))
+	for i, v := range s {
+		value, err := Float32(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Int64 converts the given string representation of an integer into int64.
+func Int64(val string) (int64, error) {
+	return strconv.ParseInt(val, 0, 64)
+}
+
+// Int64Slice converts 'val' where individual integers are separated by
+// 'sep' into a int64 slice.
+func Int64Slice(val, sep string) ([]int64, error) {
+	s := strings.Split(val, sep)
+	values := make([]int64, len(s))
+	for i, v := range s {
+		value, err := Int64(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Int32 converts the given string representation of an integer into int32.
+func Int32(val string) (int32, error) {
+	i, err := strconv.ParseInt(val, 0, 32)
+	if err != nil {
+		return 0, err
+	}
+	return int32(i), nil
+}
+
+// Int32Slice converts 'val' where individual integers are separated by
+// 'sep' into a int32 slice.
+func Int32Slice(val, sep string) ([]int32, error) {
+	s := strings.Split(val, sep)
+	values := make([]int32, len(s))
+	for i, v := range s {
+		value, err := Int32(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Uint64 converts the given string representation of an integer into uint64.
+func Uint64(val string) (uint64, error) {
+	return strconv.ParseUint(val, 0, 64)
+}
+
+// Uint64Slice converts 'val' where individual integers are separated by
+// 'sep' into a uint64 slice.
+func Uint64Slice(val, sep string) ([]uint64, error) {
+	s := strings.Split(val, sep)
+	values := make([]uint64, len(s))
+	for i, v := range s {
+		value, err := Uint64(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Uint32 converts the given string representation of an integer into uint32.
+func Uint32(val string) (uint32, error) {
+	i, err := strconv.ParseUint(val, 0, 32)
+	if err != nil {
+		return 0, err
+	}
+	return uint32(i), nil
+}
+
+// Uint32Slice converts 'val' where individual integers are separated by
+// 'sep' into a uint32 slice.
+func Uint32Slice(val, sep string) ([]uint32, error) {
+	s := strings.Split(val, sep)
+	values := make([]uint32, len(s))
+	for i, v := range s {
+		value, err := Uint32(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Bytes converts the given string representation of a byte sequence into a slice of bytes
+// A bytes sequence is encoded in URL-safe base64 without padding
+func Bytes(val string) ([]byte, error) {
+	b, err := base64.StdEncoding.DecodeString(val)
+	if err != nil {
+		b, err = base64.URLEncoding.DecodeString(val)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return b, nil
+}
+
+// BytesSlice converts 'val' where individual bytes sequences, encoded in URL-safe
+// base64 without padding, are separated by 'sep' into a slice of bytes slices slice.
+func BytesSlice(val, sep string) ([][]byte, error) {
+	s := strings.Split(val, sep)
+	values := make([][]byte, len(s))
+	for i, v := range s {
+		value, err := Bytes(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Timestamp converts the given RFC3339 formatted string into a timestamp.Timestamp.
+func Timestamp(val string) (*timestamp.Timestamp, error) {
+	var r *timestamp.Timestamp
+	err := jsonpb.UnmarshalString(val, r)
+	return r, err
+}
+
+// Duration converts the given string into a timestamp.Duration.
+func Duration(val string) (*duration.Duration, error) {
+	var r *duration.Duration
+	err := jsonpb.UnmarshalString(val, r)
+	return r, err
+}
+
+// Enum converts the given string into an int32 that should be type casted into the
+// correct enum proto type.
+func Enum(val string, enumValMap map[string]int32) (int32, error) {
+	e, ok := enumValMap[val]
+	if ok {
+		return e, nil
+	}
+
+	i, err := Int32(val)
+	if err != nil {
+		return 0, fmt.Errorf("%s is not valid", val)
+	}
+	for _, v := range enumValMap {
+		if v == i {
+			return i, nil
+		}
+	}
+	return 0, fmt.Errorf("%s is not valid", val)
+}
+
+// EnumSlice converts 'val' where individual enums are separated by 'sep'
+// into a int32 slice. Each individual int32 should be type casted into the
+// correct enum proto type.
+func EnumSlice(val, sep string, enumValMap map[string]int32) ([]int32, error) {
+	s := strings.Split(val, sep)
+	values := make([]int32, len(s))
+	for i, v := range s {
+		value, err := Enum(v, enumValMap)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/doc.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/doc.go
new file mode 100644
index 0000000..b6e5ddf
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/doc.go
@@ -0,0 +1,5 @@
+/*
+Package runtime contains runtime helper functions used by
+servers which protoc-gen-grpc-gateway generates.
+*/
+package runtime
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/errors.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/errors.go
new file mode 100644
index 0000000..b39f55e
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/errors.go
@@ -0,0 +1,136 @@
+package runtime
+
+import (
+	"context"
+	"io"
+	"net/http"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes/any"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+// HTTPStatusFromCode converts a gRPC error code into the corresponding HTTP response status.
+// See: https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
+func HTTPStatusFromCode(code codes.Code) int {
+	switch code {
+	case codes.OK:
+		return http.StatusOK
+	case codes.Canceled:
+		return http.StatusRequestTimeout
+	case codes.Unknown:
+		return http.StatusInternalServerError
+	case codes.InvalidArgument:
+		return http.StatusBadRequest
+	case codes.DeadlineExceeded:
+		return http.StatusGatewayTimeout
+	case codes.NotFound:
+		return http.StatusNotFound
+	case codes.AlreadyExists:
+		return http.StatusConflict
+	case codes.PermissionDenied:
+		return http.StatusForbidden
+	case codes.Unauthenticated:
+		return http.StatusUnauthorized
+	case codes.ResourceExhausted:
+		return http.StatusTooManyRequests
+	case codes.FailedPrecondition:
+		return http.StatusPreconditionFailed
+	case codes.Aborted:
+		return http.StatusConflict
+	case codes.OutOfRange:
+		return http.StatusBadRequest
+	case codes.Unimplemented:
+		return http.StatusNotImplemented
+	case codes.Internal:
+		return http.StatusInternalServerError
+	case codes.Unavailable:
+		return http.StatusServiceUnavailable
+	case codes.DataLoss:
+		return http.StatusInternalServerError
+	}
+
+	grpclog.Infof("Unknown gRPC error code: %v", code)
+	return http.StatusInternalServerError
+}
+
+var (
+	// HTTPError replies to the request with the error.
+	// You can set a custom function to this variable to customize error format.
+	HTTPError = DefaultHTTPError
+	// OtherErrorHandler handles the following error used by the gateway: StatusMethodNotAllowed StatusNotFound and StatusBadRequest
+	OtherErrorHandler = DefaultOtherErrorHandler
+)
+
+type errorBody struct {
+	Error   string     `protobuf:"bytes,1,name=error" json:"error"`
+	// This is to make the error more compatible with users that expect errors to be Status objects:
+	// https://github.com/grpc/grpc/blob/master/src/proto/grpc/status/status.proto
+	// It should be the exact same message as the Error field.
+	Message string     `protobuf:"bytes,1,name=message" json:"message"`
+	Code    int32      `protobuf:"varint,2,name=code" json:"code"`
+	Details []*any.Any `protobuf:"bytes,3,rep,name=details" json:"details,omitempty"`
+}
+
+// Make this also conform to proto.Message for builtin JSONPb Marshaler
+func (e *errorBody) Reset()         { *e = errorBody{} }
+func (e *errorBody) String() string { return proto.CompactTextString(e) }
+func (*errorBody) ProtoMessage()    {}
+
+// DefaultHTTPError is the default implementation of HTTPError.
+// If "err" is an error from gRPC system, the function replies with the status code mapped by HTTPStatusFromCode.
+// If otherwise, it replies with http.StatusInternalServerError.
+//
+// The response body returned by this function is a JSON object,
+// which contains a member whose key is "error" and whose value is err.Error().
+func DefaultHTTPError(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, _ *http.Request, err error) {
+	const fallback = `{"error": "failed to marshal error message"}`
+
+	w.Header().Del("Trailer")
+	w.Header().Set("Content-Type", marshaler.ContentType())
+
+	s, ok := status.FromError(err)
+	if !ok {
+		s = status.New(codes.Unknown, err.Error())
+	}
+
+	body := &errorBody{
+		Error:   s.Message(),
+		Message: s.Message(),
+		Code:    int32(s.Code()),
+		Details: s.Proto().GetDetails(),
+	}
+
+	buf, merr := marshaler.Marshal(body)
+	if merr != nil {
+		grpclog.Infof("Failed to marshal error message %q: %v", body, merr)
+		w.WriteHeader(http.StatusInternalServerError)
+		if _, err := io.WriteString(w, fallback); err != nil {
+			grpclog.Infof("Failed to write response: %v", err)
+		}
+		return
+	}
+
+	md, ok := ServerMetadataFromContext(ctx)
+	if !ok {
+		grpclog.Infof("Failed to extract ServerMetadata from context")
+	}
+
+	handleForwardResponseServerMetadata(w, mux, md)
+	handleForwardResponseTrailerHeader(w, md)
+	st := HTTPStatusFromCode(s.Code())
+	w.WriteHeader(st)
+	if _, err := w.Write(buf); err != nil {
+		grpclog.Infof("Failed to write response: %v", err)
+	}
+
+	handleForwardResponseTrailer(w, md)
+}
+
+// DefaultOtherErrorHandler is the default implementation of OtherErrorHandler.
+// It simply writes a string representation of the given error into "w".
+func DefaultOtherErrorHandler(w http.ResponseWriter, _ *http.Request, msg string, code int) {
+	http.Error(w, msg, code)
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/handler.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/handler.go
new file mode 100644
index 0000000..8ad9d76
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/handler.go
@@ -0,0 +1,206 @@
+package runtime
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/textproto"
+
+	"context"
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes/any"
+	"github.com/grpc-ecosystem/grpc-gateway/runtime/internal"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+// ForwardResponseStream forwards the stream from gRPC server to REST client.
+func ForwardResponseStream(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, req *http.Request, recv func() (proto.Message, error), opts ...func(context.Context, http.ResponseWriter, proto.Message) error) {
+	f, ok := w.(http.Flusher)
+	if !ok {
+		grpclog.Infof("Flush not supported in %T", w)
+		http.Error(w, "unexpected type of web server", http.StatusInternalServerError)
+		return
+	}
+
+	md, ok := ServerMetadataFromContext(ctx)
+	if !ok {
+		grpclog.Infof("Failed to extract ServerMetadata from context")
+		http.Error(w, "unexpected error", http.StatusInternalServerError)
+		return
+	}
+	handleForwardResponseServerMetadata(w, mux, md)
+
+	w.Header().Set("Transfer-Encoding", "chunked")
+	w.Header().Set("Content-Type", marshaler.ContentType())
+	if err := handleForwardResponseOptions(ctx, w, nil, opts); err != nil {
+		HTTPError(ctx, mux, marshaler, w, req, err)
+		return
+	}
+
+	var delimiter []byte
+	if d, ok := marshaler.(Delimited); ok {
+		delimiter = d.Delimiter()
+	} else {
+		delimiter = []byte("\n")
+	}
+
+	var wroteHeader bool
+	for {
+		resp, err := recv()
+		if err == io.EOF {
+			return
+		}
+		if err != nil {
+			handleForwardResponseStreamError(wroteHeader, marshaler, w, err)
+			return
+		}
+		if err := handleForwardResponseOptions(ctx, w, resp, opts); err != nil {
+			handleForwardResponseStreamError(wroteHeader, marshaler, w, err)
+			return
+		}
+
+		buf, err := marshaler.Marshal(streamChunk(resp, nil))
+		if err != nil {
+			grpclog.Infof("Failed to marshal response chunk: %v", err)
+			handleForwardResponseStreamError(wroteHeader, marshaler, w, err)
+			return
+		}
+		if _, err = w.Write(buf); err != nil {
+			grpclog.Infof("Failed to send response chunk: %v", err)
+			return
+		}
+		wroteHeader = true
+		if _, err = w.Write(delimiter); err != nil {
+			grpclog.Infof("Failed to send delimiter chunk: %v", err)
+			return
+		}
+		f.Flush()
+	}
+}
+
+func handleForwardResponseServerMetadata(w http.ResponseWriter, mux *ServeMux, md ServerMetadata) {
+	for k, vs := range md.HeaderMD {
+		if h, ok := mux.outgoingHeaderMatcher(k); ok {
+			for _, v := range vs {
+				w.Header().Add(h, v)
+			}
+		}
+	}
+}
+
+func handleForwardResponseTrailerHeader(w http.ResponseWriter, md ServerMetadata) {
+	for k := range md.TrailerMD {
+		tKey := textproto.CanonicalMIMEHeaderKey(fmt.Sprintf("%s%s", MetadataTrailerPrefix, k))
+		w.Header().Add("Trailer", tKey)
+	}
+}
+
+func handleForwardResponseTrailer(w http.ResponseWriter, md ServerMetadata) {
+	for k, vs := range md.TrailerMD {
+		tKey := fmt.Sprintf("%s%s", MetadataTrailerPrefix, k)
+		for _, v := range vs {
+			w.Header().Add(tKey, v)
+		}
+	}
+}
+
+// responseBody interface contains method for getting field for marshaling to the response body
+// this method is generated for response struct from the value of `response_body` in the `google.api.HttpRule`
+type responseBody interface {
+	XXX_ResponseBody() interface{}
+}
+
+// ForwardResponseMessage forwards the message "resp" from gRPC server to REST client.
+func ForwardResponseMessage(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, req *http.Request, resp proto.Message, opts ...func(context.Context, http.ResponseWriter, proto.Message) error) {
+	md, ok := ServerMetadataFromContext(ctx)
+	if !ok {
+		grpclog.Infof("Failed to extract ServerMetadata from context")
+	}
+
+	handleForwardResponseServerMetadata(w, mux, md)
+	handleForwardResponseTrailerHeader(w, md)
+	w.Header().Set("Content-Type", marshaler.ContentType())
+	if err := handleForwardResponseOptions(ctx, w, resp, opts); err != nil {
+		HTTPError(ctx, mux, marshaler, w, req, err)
+		return
+	}
+	var buf []byte
+	var err error
+	if rb, ok := resp.(responseBody); ok {
+		buf, err = marshaler.Marshal(rb.XXX_ResponseBody())
+	} else {
+		buf, err = marshaler.Marshal(resp)
+	}
+	if err != nil {
+		grpclog.Infof("Marshal error: %v", err)
+		HTTPError(ctx, mux, marshaler, w, req, err)
+		return
+	}
+
+	if _, err = w.Write(buf); err != nil {
+		grpclog.Infof("Failed to write response: %v", err)
+	}
+
+	handleForwardResponseTrailer(w, md)
+}
+
+func handleForwardResponseOptions(ctx context.Context, w http.ResponseWriter, resp proto.Message, opts []func(context.Context, http.ResponseWriter, proto.Message) error) error {
+	if len(opts) == 0 {
+		return nil
+	}
+	for _, opt := range opts {
+		if err := opt(ctx, w, resp); err != nil {
+			grpclog.Infof("Error handling ForwardResponseOptions: %v", err)
+			return err
+		}
+	}
+	return nil
+}
+
+func handleForwardResponseStreamError(wroteHeader bool, marshaler Marshaler, w http.ResponseWriter, err error) {
+	buf, merr := marshaler.Marshal(streamChunk(nil, err))
+	if merr != nil {
+		grpclog.Infof("Failed to marshal an error: %v", merr)
+		return
+	}
+	if !wroteHeader {
+		s, ok := status.FromError(err)
+		if !ok {
+			s = status.New(codes.Unknown, err.Error())
+		}
+		w.WriteHeader(HTTPStatusFromCode(s.Code()))
+	}
+	if _, werr := w.Write(buf); werr != nil {
+		grpclog.Infof("Failed to notify error to client: %v", werr)
+		return
+	}
+}
+
+func streamChunk(result proto.Message, err error) map[string]proto.Message {
+	if err != nil {
+		grpcCode := codes.Unknown
+		grpcMessage := err.Error()
+		var grpcDetails []*any.Any
+		if s, ok := status.FromError(err); ok {
+			grpcCode = s.Code()
+			grpcMessage = s.Message()
+			grpcDetails = s.Proto().GetDetails()
+		}
+		httpCode := HTTPStatusFromCode(grpcCode)
+		return map[string]proto.Message{
+			"error": &internal.StreamError{
+				GrpcCode:   int32(grpcCode),
+				HttpCode:   int32(httpCode),
+				Message:    grpcMessage,
+				HttpStatus: http.StatusText(httpCode),
+				Details:    grpcDetails,
+			},
+		}
+	}
+	if result == nil {
+		return streamChunk(nil, fmt.Errorf("empty response"))
+	}
+	return map[string]proto.Message{"result": result}
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/internal/BUILD.bazel b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/internal/BUILD.bazel
new file mode 100644
index 0000000..937e660
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/internal/BUILD.bazel
@@ -0,0 +1,23 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
+
+package(default_visibility = ["//runtime:__subpackages__"])
+
+proto_library(
+    name = "internal_proto",
+    srcs = ["stream_chunk.proto"],
+    deps = ["@com_google_protobuf//:any_proto"],
+)
+
+go_proto_library(
+    name = "internal_go_proto",
+    importpath = "github.com/grpc-ecosystem/grpc-gateway/runtime/internal",
+    proto = ":internal_proto",
+    deps = ["@com_github_golang_protobuf//ptypes/any:go_default_library"],
+)
+
+go_library(
+    name = "go_default_library",
+    embed = [":internal_go_proto"],
+    importpath = "github.com/grpc-ecosystem/grpc-gateway/runtime/internal",
+)
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/internal/stream_chunk.proto b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/internal/stream_chunk.proto
new file mode 100644
index 0000000..55f42ce
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/internal/stream_chunk.proto
@@ -0,0 +1,15 @@
+syntax = "proto3";
+package grpc.gateway.runtime;
+option go_package = "internal";
+
+import "google/protobuf/any.proto";
+
+// StreamError is a response type which is returned when
+// streaming rpc returns an error.
+message StreamError {
+	int32 grpc_code = 1;
+	int32 http_code = 2;
+	string message = 3;
+	string http_status = 4;
+	repeated google.protobuf.Any details = 5;
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_json.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_json.go
new file mode 100644
index 0000000..f9d3a58
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_json.go
@@ -0,0 +1,45 @@
+package runtime
+
+import (
+	"encoding/json"
+	"io"
+)
+
+// JSONBuiltin is a Marshaler which marshals/unmarshals into/from JSON
+// with the standard "encoding/json" package of Golang.
+// Although it is generally faster for simple proto messages than JSONPb,
+// it does not support advanced features of protobuf, e.g. map, oneof, ....
+//
+// The NewEncoder and NewDecoder types return *json.Encoder and
+// *json.Decoder respectively.
+type JSONBuiltin struct{}
+
+// ContentType always Returns "application/json".
+func (*JSONBuiltin) ContentType() string {
+	return "application/json"
+}
+
+// Marshal marshals "v" into JSON
+func (j *JSONBuiltin) Marshal(v interface{}) ([]byte, error) {
+	return json.Marshal(v)
+}
+
+// Unmarshal unmarshals JSON data into "v".
+func (j *JSONBuiltin) Unmarshal(data []byte, v interface{}) error {
+	return json.Unmarshal(data, v)
+}
+
+// NewDecoder returns a Decoder which reads JSON stream from "r".
+func (j *JSONBuiltin) NewDecoder(r io.Reader) Decoder {
+	return json.NewDecoder(r)
+}
+
+// NewEncoder returns an Encoder which writes JSON stream into "w".
+func (j *JSONBuiltin) NewEncoder(w io.Writer) Encoder {
+	return json.NewEncoder(w)
+}
+
+// Delimiter for newline encoded JSON streams.
+func (j *JSONBuiltin) Delimiter() []byte {
+	return []byte("\n")
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_jsonpb.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_jsonpb.go
new file mode 100644
index 0000000..f56072a
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_jsonpb.go
@@ -0,0 +1,203 @@
+package runtime
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"reflect"
+
+	"github.com/golang/protobuf/jsonpb"
+	"github.com/golang/protobuf/proto"
+)
+
+// JSONPb is a Marshaler which marshals/unmarshals into/from JSON
+// with the "github.com/golang/protobuf/jsonpb".
+// It supports fully functionality of protobuf unlike JSONBuiltin.
+//
+// The NewDecoder method returns a DecoderWrapper, so the underlying
+// *json.Decoder methods can be used.
+type JSONPb jsonpb.Marshaler
+
+// ContentType always returns "application/json".
+func (*JSONPb) ContentType() string {
+	return "application/json"
+}
+
+// Marshal marshals "v" into JSON.
+func (j *JSONPb) Marshal(v interface{}) ([]byte, error) {
+	if _, ok := v.(proto.Message); !ok {
+		return j.marshalNonProtoField(v)
+	}
+
+	var buf bytes.Buffer
+	if err := j.marshalTo(&buf, v); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func (j *JSONPb) marshalTo(w io.Writer, v interface{}) error {
+	p, ok := v.(proto.Message)
+	if !ok {
+		buf, err := j.marshalNonProtoField(v)
+		if err != nil {
+			return err
+		}
+		_, err = w.Write(buf)
+		return err
+	}
+	return (*jsonpb.Marshaler)(j).Marshal(w, p)
+}
+
+// marshalNonProto marshals a non-message field of a protobuf message.
+// This function does not correctly marshals arbitrary data structure into JSON,
+// but it is only capable of marshaling non-message field values of protobuf,
+// i.e. primitive types, enums; pointers to primitives or enums; maps from
+// integer/string types to primitives/enums/pointers to messages.
+func (j *JSONPb) marshalNonProtoField(v interface{}) ([]byte, error) {
+	if v == nil {
+		return []byte("null"), nil
+	}
+	rv := reflect.ValueOf(v)
+	for rv.Kind() == reflect.Ptr {
+		if rv.IsNil() {
+			return []byte("null"), nil
+		}
+		rv = rv.Elem()
+	}
+
+	if rv.Kind() == reflect.Map {
+		m := make(map[string]*json.RawMessage)
+		for _, k := range rv.MapKeys() {
+			buf, err := j.Marshal(rv.MapIndex(k).Interface())
+			if err != nil {
+				return nil, err
+			}
+			m[fmt.Sprintf("%v", k.Interface())] = (*json.RawMessage)(&buf)
+		}
+		if j.Indent != "" {
+			return json.MarshalIndent(m, "", j.Indent)
+		}
+		return json.Marshal(m)
+	}
+	if enum, ok := rv.Interface().(protoEnum); ok && !j.EnumsAsInts {
+		return json.Marshal(enum.String())
+	}
+	return json.Marshal(rv.Interface())
+}
+
+// Unmarshal unmarshals JSON "data" into "v"
+func (j *JSONPb) Unmarshal(data []byte, v interface{}) error {
+	return unmarshalJSONPb(data, v)
+}
+
+// NewDecoder returns a Decoder which reads JSON stream from "r".
+func (j *JSONPb) NewDecoder(r io.Reader) Decoder {
+	d := json.NewDecoder(r)
+	return DecoderWrapper{Decoder: d}
+}
+
+// DecoderWrapper is a wrapper around a *json.Decoder that adds
+// support for protos to the Decode method.
+type DecoderWrapper struct {
+	*json.Decoder
+}
+
+// Decode wraps the embedded decoder's Decode method to support
+// protos using a jsonpb.Unmarshaler.
+func (d DecoderWrapper) Decode(v interface{}) error {
+	return decodeJSONPb(d.Decoder, v)
+}
+
+// NewEncoder returns an Encoder which writes JSON stream into "w".
+func (j *JSONPb) NewEncoder(w io.Writer) Encoder {
+	return EncoderFunc(func(v interface{}) error { return j.marshalTo(w, v) })
+}
+
+func unmarshalJSONPb(data []byte, v interface{}) error {
+	d := json.NewDecoder(bytes.NewReader(data))
+	return decodeJSONPb(d, v)
+}
+
+func decodeJSONPb(d *json.Decoder, v interface{}) error {
+	p, ok := v.(proto.Message)
+	if !ok {
+		return decodeNonProtoField(d, v)
+	}
+	unmarshaler := &jsonpb.Unmarshaler{AllowUnknownFields: true}
+	return unmarshaler.UnmarshalNext(d, p)
+}
+
+func decodeNonProtoField(d *json.Decoder, v interface{}) error {
+	rv := reflect.ValueOf(v)
+	if rv.Kind() != reflect.Ptr {
+		return fmt.Errorf("%T is not a pointer", v)
+	}
+	for rv.Kind() == reflect.Ptr {
+		if rv.IsNil() {
+			rv.Set(reflect.New(rv.Type().Elem()))
+		}
+		if rv.Type().ConvertibleTo(typeProtoMessage) {
+			unmarshaler := &jsonpb.Unmarshaler{AllowUnknownFields: true}
+			return unmarshaler.UnmarshalNext(d, rv.Interface().(proto.Message))
+		}
+		rv = rv.Elem()
+	}
+	if rv.Kind() == reflect.Map {
+		if rv.IsNil() {
+			rv.Set(reflect.MakeMap(rv.Type()))
+		}
+		conv, ok := convFromType[rv.Type().Key().Kind()]
+		if !ok {
+			return fmt.Errorf("unsupported type of map field key: %v", rv.Type().Key())
+		}
+
+		m := make(map[string]*json.RawMessage)
+		if err := d.Decode(&m); err != nil {
+			return err
+		}
+		for k, v := range m {
+			result := conv.Call([]reflect.Value{reflect.ValueOf(k)})
+			if err := result[1].Interface(); err != nil {
+				return err.(error)
+			}
+			bk := result[0]
+			bv := reflect.New(rv.Type().Elem())
+			if err := unmarshalJSONPb([]byte(*v), bv.Interface()); err != nil {
+				return err
+			}
+			rv.SetMapIndex(bk, bv.Elem())
+		}
+		return nil
+	}
+	if _, ok := rv.Interface().(protoEnum); ok {
+		var repr interface{}
+		if err := d.Decode(&repr); err != nil {
+			return err
+		}
+		switch repr.(type) {
+		case string:
+			// TODO(yugui) Should use proto.StructProperties?
+			return fmt.Errorf("unmarshaling of symbolic enum %q not supported: %T", repr, rv.Interface())
+		case float64:
+			rv.Set(reflect.ValueOf(int32(repr.(float64))).Convert(rv.Type()))
+			return nil
+		default:
+			return fmt.Errorf("cannot assign %#v into Go type %T", repr, rv.Interface())
+		}
+	}
+	return d.Decode(v)
+}
+
+type protoEnum interface {
+	fmt.Stringer
+	EnumDescriptor() ([]byte, []int)
+}
+
+var typeProtoMessage = reflect.TypeOf((*proto.Message)(nil)).Elem()
+
+// Delimiter for newline encoded JSON streams.
+func (j *JSONPb) Delimiter() []byte {
+	return []byte("\n")
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_proto.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_proto.go
new file mode 100644
index 0000000..f65d1a2
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_proto.go
@@ -0,0 +1,62 @@
+package runtime
+
+import (
+	"io"
+
+	"errors"
+	"github.com/golang/protobuf/proto"
+	"io/ioutil"
+)
+
+// ProtoMarshaller is a Marshaller which marshals/unmarshals into/from serialize proto bytes
+type ProtoMarshaller struct{}
+
+// ContentType always returns "application/octet-stream".
+func (*ProtoMarshaller) ContentType() string {
+	return "application/octet-stream"
+}
+
+// Marshal marshals "value" into Proto
+func (*ProtoMarshaller) Marshal(value interface{}) ([]byte, error) {
+	message, ok := value.(proto.Message)
+	if !ok {
+		return nil, errors.New("unable to marshal non proto field")
+	}
+	return proto.Marshal(message)
+}
+
+// Unmarshal unmarshals proto "data" into "value"
+func (*ProtoMarshaller) Unmarshal(data []byte, value interface{}) error {
+	message, ok := value.(proto.Message)
+	if !ok {
+		return errors.New("unable to unmarshal non proto field")
+	}
+	return proto.Unmarshal(data, message)
+}
+
+// NewDecoder returns a Decoder which reads proto stream from "reader".
+func (marshaller *ProtoMarshaller) NewDecoder(reader io.Reader) Decoder {
+	return DecoderFunc(func(value interface{}) error {
+		buffer, err := ioutil.ReadAll(reader)
+		if err != nil {
+			return err
+		}
+		return marshaller.Unmarshal(buffer, value)
+	})
+}
+
+// NewEncoder returns an Encoder which writes proto stream into "writer".
+func (marshaller *ProtoMarshaller) NewEncoder(writer io.Writer) Encoder {
+	return EncoderFunc(func(value interface{}) error {
+		buffer, err := marshaller.Marshal(value)
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write(buffer)
+		if err != nil {
+			return err
+		}
+
+		return nil
+	})
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler.go
new file mode 100644
index 0000000..98fe6e8
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler.go
@@ -0,0 +1,48 @@
+package runtime
+
+import (
+	"io"
+)
+
+// Marshaler defines a conversion between byte sequence and gRPC payloads / fields.
+type Marshaler interface {
+	// Marshal marshals "v" into byte sequence.
+	Marshal(v interface{}) ([]byte, error)
+	// Unmarshal unmarshals "data" into "v".
+	// "v" must be a pointer value.
+	Unmarshal(data []byte, v interface{}) error
+	// NewDecoder returns a Decoder which reads byte sequence from "r".
+	NewDecoder(r io.Reader) Decoder
+	// NewEncoder returns an Encoder which writes bytes sequence into "w".
+	NewEncoder(w io.Writer) Encoder
+	// ContentType returns the Content-Type which this marshaler is responsible for.
+	ContentType() string
+}
+
+// Decoder decodes a byte sequence
+type Decoder interface {
+	Decode(v interface{}) error
+}
+
+// Encoder encodes gRPC payloads / fields into byte sequence.
+type Encoder interface {
+	Encode(v interface{}) error
+}
+
+// DecoderFunc adapts an decoder function into Decoder.
+type DecoderFunc func(v interface{}) error
+
+// Decode delegates invocations to the underlying function itself.
+func (f DecoderFunc) Decode(v interface{}) error { return f(v) }
+
+// EncoderFunc adapts an encoder function into Encoder
+type EncoderFunc func(v interface{}) error
+
+// Encode delegates invocations to the underlying function itself.
+func (f EncoderFunc) Encode(v interface{}) error { return f(v) }
+
+// Delimited defines the streaming delimiter.
+type Delimited interface {
+	// Delimiter returns the record seperator for the stream.
+	Delimiter() []byte
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler_registry.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler_registry.go
new file mode 100644
index 0000000..5cc53ae
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler_registry.go
@@ -0,0 +1,91 @@
+package runtime
+
+import (
+	"errors"
+	"net/http"
+)
+
+// MIMEWildcard is the fallback MIME type used for requests which do not match
+// a registered MIME type.
+const MIMEWildcard = "*"
+
+var (
+	acceptHeader      = http.CanonicalHeaderKey("Accept")
+	contentTypeHeader = http.CanonicalHeaderKey("Content-Type")
+
+	defaultMarshaler = &JSONPb{OrigName: true}
+)
+
+// MarshalerForRequest returns the inbound/outbound marshalers for this request.
+// It checks the registry on the ServeMux for the MIME type set by the Content-Type header.
+// If it isn't set (or the request Content-Type is empty), checks for "*".
+// If there are multiple Content-Type headers set, choose the first one that it can
+// exactly match in the registry.
+// Otherwise, it follows the above logic for "*"/InboundMarshaler/OutboundMarshaler.
+func MarshalerForRequest(mux *ServeMux, r *http.Request) (inbound Marshaler, outbound Marshaler) {
+	for _, acceptVal := range r.Header[acceptHeader] {
+		if m, ok := mux.marshalers.mimeMap[acceptVal]; ok {
+			outbound = m
+			break
+		}
+	}
+
+	for _, contentTypeVal := range r.Header[contentTypeHeader] {
+		if m, ok := mux.marshalers.mimeMap[contentTypeVal]; ok {
+			inbound = m
+			break
+		}
+	}
+
+	if inbound == nil {
+		inbound = mux.marshalers.mimeMap[MIMEWildcard]
+	}
+	if outbound == nil {
+		outbound = inbound
+	}
+
+	return inbound, outbound
+}
+
+// marshalerRegistry is a mapping from MIME types to Marshalers.
+type marshalerRegistry struct {
+	mimeMap map[string]Marshaler
+}
+
+// add adds a marshaler for a case-sensitive MIME type string ("*" to match any
+// MIME type).
+func (m marshalerRegistry) add(mime string, marshaler Marshaler) error {
+	if len(mime) == 0 {
+		return errors.New("empty MIME type")
+	}
+
+	m.mimeMap[mime] = marshaler
+
+	return nil
+}
+
+// makeMarshalerMIMERegistry returns a new registry of marshalers.
+// It allows for a mapping of case-sensitive Content-Type MIME type string to runtime.Marshaler interfaces.
+//
+// For example, you could allow the client to specify the use of the runtime.JSONPb marshaler
+// with a "application/jsonpb" Content-Type and the use of the runtime.JSONBuiltin marshaler
+// with a "application/json" Content-Type.
+// "*" can be used to match any Content-Type.
+// This can be attached to a ServerMux with the marshaler option.
+func makeMarshalerMIMERegistry() marshalerRegistry {
+	return marshalerRegistry{
+		mimeMap: map[string]Marshaler{
+			MIMEWildcard: defaultMarshaler,
+		},
+	}
+}
+
+// WithMarshalerOption returns a ServeMuxOption which associates inbound and outbound
+// Marshalers to a MIME type in mux.
+func WithMarshalerOption(mime string, marshaler Marshaler) ServeMuxOption {
+	return func(mux *ServeMux) {
+		if err := mux.marshalers.add(mime, marshaler); err != nil {
+			panic(err)
+		}
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/mux.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/mux.go
new file mode 100644
index 0000000..463084a
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/mux.go
@@ -0,0 +1,258 @@
+package runtime
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/golang/protobuf/proto"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+// A HandlerFunc handles a specific pair of path pattern and HTTP method.
+type HandlerFunc func(w http.ResponseWriter, r *http.Request, pathParams map[string]string)
+
+// ServeMux is a request multiplexer for grpc-gateway.
+// It matches http requests to patterns and invokes the corresponding handler.
+type ServeMux struct {
+	// handlers maps HTTP method to a list of handlers.
+	handlers               map[string][]handler
+	forwardResponseOptions []func(context.Context, http.ResponseWriter, proto.Message) error
+	marshalers             marshalerRegistry
+	incomingHeaderMatcher  HeaderMatcherFunc
+	outgoingHeaderMatcher  HeaderMatcherFunc
+	metadataAnnotators     []func(context.Context, *http.Request) metadata.MD
+	protoErrorHandler      ProtoErrorHandlerFunc
+}
+
+// ServeMuxOption is an option that can be given to a ServeMux on construction.
+type ServeMuxOption func(*ServeMux)
+
+// WithForwardResponseOption returns a ServeMuxOption representing the forwardResponseOption.
+//
+// forwardResponseOption is an option that will be called on the relevant context.Context,
+// http.ResponseWriter, and proto.Message before every forwarded response.
+//
+// The message may be nil in the case where just a header is being sent.
+func WithForwardResponseOption(forwardResponseOption func(context.Context, http.ResponseWriter, proto.Message) error) ServeMuxOption {
+	return func(serveMux *ServeMux) {
+		serveMux.forwardResponseOptions = append(serveMux.forwardResponseOptions, forwardResponseOption)
+	}
+}
+
+// HeaderMatcherFunc checks whether a header key should be forwarded to/from gRPC context.
+type HeaderMatcherFunc func(string) (string, bool)
+
+// DefaultHeaderMatcher is used to pass http request headers to/from gRPC context. This adds permanent HTTP header
+// keys (as specified by the IANA) to gRPC context with grpcgateway- prefix. HTTP headers that start with
+// 'Grpc-Metadata-' are mapped to gRPC metadata after removing prefix 'Grpc-Metadata-'.
+func DefaultHeaderMatcher(key string) (string, bool) {
+	if isPermanentHTTPHeader(key) {
+		return MetadataPrefix + key, true
+	} else if strings.HasPrefix(key, MetadataHeaderPrefix) {
+		return key[len(MetadataHeaderPrefix):], true
+	}
+	return "", false
+}
+
+// WithIncomingHeaderMatcher returns a ServeMuxOption representing a headerMatcher for incoming request to gateway.
+//
+// This matcher will be called with each header in http.Request. If matcher returns true, that header will be
+// passed to gRPC context. To transform the header before passing to gRPC context, matcher should return modified header.
+func WithIncomingHeaderMatcher(fn HeaderMatcherFunc) ServeMuxOption {
+	return func(mux *ServeMux) {
+		mux.incomingHeaderMatcher = fn
+	}
+}
+
+// WithOutgoingHeaderMatcher returns a ServeMuxOption representing a headerMatcher for outgoing response from gateway.
+//
+// This matcher will be called with each header in response header metadata. If matcher returns true, that header will be
+// passed to http response returned from gateway. To transform the header before passing to response,
+// matcher should return modified header.
+func WithOutgoingHeaderMatcher(fn HeaderMatcherFunc) ServeMuxOption {
+	return func(mux *ServeMux) {
+		mux.outgoingHeaderMatcher = fn
+	}
+}
+
+// WithMetadata returns a ServeMuxOption for passing metadata to a gRPC context.
+//
+// This can be used by services that need to read from http.Request and modify gRPC context. A common use case
+// is reading token from cookie and adding it in gRPC context.
+func WithMetadata(annotator func(context.Context, *http.Request) metadata.MD) ServeMuxOption {
+	return func(serveMux *ServeMux) {
+		serveMux.metadataAnnotators = append(serveMux.metadataAnnotators, annotator)
+	}
+}
+
+// WithProtoErrorHandler returns a ServeMuxOption for passing metadata to a gRPC context.
+//
+// This can be used to handle an error as general proto message defined by gRPC.
+// The response including body and status is not backward compatible with the default error handler.
+// When this option is used, HTTPError and OtherErrorHandler are overwritten on initialization.
+func WithProtoErrorHandler(fn ProtoErrorHandlerFunc) ServeMuxOption {
+	return func(serveMux *ServeMux) {
+		serveMux.protoErrorHandler = fn
+	}
+}
+
+// NewServeMux returns a new ServeMux whose internal mapping is empty.
+func NewServeMux(opts ...ServeMuxOption) *ServeMux {
+	serveMux := &ServeMux{
+		handlers:               make(map[string][]handler),
+		forwardResponseOptions: make([]func(context.Context, http.ResponseWriter, proto.Message) error, 0),
+		marshalers:             makeMarshalerMIMERegistry(),
+	}
+
+	for _, opt := range opts {
+		opt(serveMux)
+	}
+
+	if serveMux.protoErrorHandler != nil {
+		HTTPError = serveMux.protoErrorHandler
+		// OtherErrorHandler is no longer used when protoErrorHandler is set.
+		// Overwritten by a special error handler to return Unknown.
+		OtherErrorHandler = func(w http.ResponseWriter, r *http.Request, _ string, _ int) {
+			ctx := context.Background()
+			_, outboundMarshaler := MarshalerForRequest(serveMux, r)
+			sterr := status.Error(codes.Unknown, "unexpected use of OtherErrorHandler")
+			serveMux.protoErrorHandler(ctx, serveMux, outboundMarshaler, w, r, sterr)
+		}
+	}
+
+	if serveMux.incomingHeaderMatcher == nil {
+		serveMux.incomingHeaderMatcher = DefaultHeaderMatcher
+	}
+
+	if serveMux.outgoingHeaderMatcher == nil {
+		serveMux.outgoingHeaderMatcher = func(key string) (string, bool) {
+			return fmt.Sprintf("%s%s", MetadataHeaderPrefix, key), true
+		}
+	}
+
+	return serveMux
+}
+
+// Handle associates "h" to the pair of HTTP method and path pattern.
+func (s *ServeMux) Handle(meth string, pat Pattern, h HandlerFunc) {
+	s.handlers[meth] = append(s.handlers[meth], handler{pat: pat, h: h})
+}
+
+// ServeHTTP dispatches the request to the first handler whose pattern matches to r.Method and r.Path.
+func (s *ServeMux) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+
+	path := r.URL.Path
+	if !strings.HasPrefix(path, "/") {
+		if s.protoErrorHandler != nil {
+			_, outboundMarshaler := MarshalerForRequest(s, r)
+			sterr := status.Error(codes.InvalidArgument, http.StatusText(http.StatusBadRequest))
+			s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, sterr)
+		} else {
+			OtherErrorHandler(w, r, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
+		}
+		return
+	}
+
+	components := strings.Split(path[1:], "/")
+	l := len(components)
+	var verb string
+	if idx := strings.LastIndex(components[l-1], ":"); idx == 0 {
+		if s.protoErrorHandler != nil {
+			_, outboundMarshaler := MarshalerForRequest(s, r)
+			sterr := status.Error(codes.Unimplemented, http.StatusText(http.StatusNotImplemented))
+			s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, sterr)
+		} else {
+			OtherErrorHandler(w, r, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+		}
+		return
+	} else if idx > 0 {
+		c := components[l-1]
+		components[l-1], verb = c[:idx], c[idx+1:]
+	}
+
+	if override := r.Header.Get("X-HTTP-Method-Override"); override != "" && isPathLengthFallback(r) {
+		r.Method = strings.ToUpper(override)
+		if err := r.ParseForm(); err != nil {
+			if s.protoErrorHandler != nil {
+				_, outboundMarshaler := MarshalerForRequest(s, r)
+				sterr := status.Error(codes.InvalidArgument, err.Error())
+				s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, sterr)
+			} else {
+				OtherErrorHandler(w, r, err.Error(), http.StatusBadRequest)
+			}
+			return
+		}
+	}
+	for _, h := range s.handlers[r.Method] {
+		pathParams, err := h.pat.Match(components, verb)
+		if err != nil {
+			continue
+		}
+		h.h(w, r, pathParams)
+		return
+	}
+
+	// lookup other methods to handle fallback from GET to POST and
+	// to determine if it is MethodNotAllowed or NotFound.
+	for m, handlers := range s.handlers {
+		if m == r.Method {
+			continue
+		}
+		for _, h := range handlers {
+			pathParams, err := h.pat.Match(components, verb)
+			if err != nil {
+				continue
+			}
+			// X-HTTP-Method-Override is optional. Always allow fallback to POST.
+			if isPathLengthFallback(r) {
+				if err := r.ParseForm(); err != nil {
+					if s.protoErrorHandler != nil {
+						_, outboundMarshaler := MarshalerForRequest(s, r)
+						sterr := status.Error(codes.InvalidArgument, err.Error())
+						s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, sterr)
+					} else {
+						OtherErrorHandler(w, r, err.Error(), http.StatusBadRequest)
+					}
+					return
+				}
+				h.h(w, r, pathParams)
+				return
+			}
+			if s.protoErrorHandler != nil {
+				_, outboundMarshaler := MarshalerForRequest(s, r)
+				sterr := status.Error(codes.Unimplemented, http.StatusText(http.StatusMethodNotAllowed))
+				s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, sterr)
+			} else {
+				OtherErrorHandler(w, r, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
+			}
+			return
+		}
+	}
+
+	if s.protoErrorHandler != nil {
+		_, outboundMarshaler := MarshalerForRequest(s, r)
+		sterr := status.Error(codes.Unimplemented, http.StatusText(http.StatusNotImplemented))
+		s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, sterr)
+	} else {
+		OtherErrorHandler(w, r, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+	}
+}
+
+// GetForwardResponseOptions returns the ForwardResponseOptions associated with this ServeMux.
+func (s *ServeMux) GetForwardResponseOptions() []func(context.Context, http.ResponseWriter, proto.Message) error {
+	return s.forwardResponseOptions
+}
+
+func isPathLengthFallback(r *http.Request) bool {
+	return r.Method == "POST" && r.Header.Get("Content-Type") == "application/x-www-form-urlencoded"
+}
+
+type handler struct {
+	pat Pattern
+	h   HandlerFunc
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/pattern.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/pattern.go
new file mode 100644
index 0000000..f16a84a
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/pattern.go
@@ -0,0 +1,227 @@
+package runtime
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/grpc-ecosystem/grpc-gateway/utilities"
+	"google.golang.org/grpc/grpclog"
+)
+
+var (
+	// ErrNotMatch indicates that the given HTTP request path does not match to the pattern.
+	ErrNotMatch = errors.New("not match to the path pattern")
+	// ErrInvalidPattern indicates that the given definition of Pattern is not valid.
+	ErrInvalidPattern = errors.New("invalid pattern")
+)
+
+type op struct {
+	code    utilities.OpCode
+	operand int
+}
+
+// Pattern is a template pattern of http request paths defined in github.com/googleapis/googleapis/google/api/http.proto.
+type Pattern struct {
+	// ops is a list of operations
+	ops []op
+	// pool is a constant pool indexed by the operands or vars.
+	pool []string
+	// vars is a list of variables names to be bound by this pattern
+	vars []string
+	// stacksize is the max depth of the stack
+	stacksize int
+	// tailLen is the length of the fixed-size segments after a deep wildcard
+	tailLen int
+	// verb is the VERB part of the path pattern. It is empty if the pattern does not have VERB part.
+	verb string
+}
+
+// NewPattern returns a new Pattern from the given definition values.
+// "ops" is a sequence of op codes. "pool" is a constant pool.
+// "verb" is the verb part of the pattern. It is empty if the pattern does not have the part.
+// "version" must be 1 for now.
+// It returns an error if the given definition is invalid.
+func NewPattern(version int, ops []int, pool []string, verb string) (Pattern, error) {
+	if version != 1 {
+		grpclog.Infof("unsupported version: %d", version)
+		return Pattern{}, ErrInvalidPattern
+	}
+
+	l := len(ops)
+	if l%2 != 0 {
+		grpclog.Infof("odd number of ops codes: %d", l)
+		return Pattern{}, ErrInvalidPattern
+	}
+
+	var (
+		typedOps        []op
+		stack, maxstack int
+		tailLen         int
+		pushMSeen       bool
+		vars            []string
+	)
+	for i := 0; i < l; i += 2 {
+		op := op{code: utilities.OpCode(ops[i]), operand: ops[i+1]}
+		switch op.code {
+		case utilities.OpNop:
+			continue
+		case utilities.OpPush:
+			if pushMSeen {
+				tailLen++
+			}
+			stack++
+		case utilities.OpPushM:
+			if pushMSeen {
+				grpclog.Infof("pushM appears twice")
+				return Pattern{}, ErrInvalidPattern
+			}
+			pushMSeen = true
+			stack++
+		case utilities.OpLitPush:
+			if op.operand < 0 || len(pool) <= op.operand {
+				grpclog.Infof("negative literal index: %d", op.operand)
+				return Pattern{}, ErrInvalidPattern
+			}
+			if pushMSeen {
+				tailLen++
+			}
+			stack++
+		case utilities.OpConcatN:
+			if op.operand <= 0 {
+				grpclog.Infof("negative concat size: %d", op.operand)
+				return Pattern{}, ErrInvalidPattern
+			}
+			stack -= op.operand
+			if stack < 0 {
+				grpclog.Print("stack underflow")
+				return Pattern{}, ErrInvalidPattern
+			}
+			stack++
+		case utilities.OpCapture:
+			if op.operand < 0 || len(pool) <= op.operand {
+				grpclog.Infof("variable name index out of bound: %d", op.operand)
+				return Pattern{}, ErrInvalidPattern
+			}
+			v := pool[op.operand]
+			op.operand = len(vars)
+			vars = append(vars, v)
+			stack--
+			if stack < 0 {
+				grpclog.Infof("stack underflow")
+				return Pattern{}, ErrInvalidPattern
+			}
+		default:
+			grpclog.Infof("invalid opcode: %d", op.code)
+			return Pattern{}, ErrInvalidPattern
+		}
+
+		if maxstack < stack {
+			maxstack = stack
+		}
+		typedOps = append(typedOps, op)
+	}
+	return Pattern{
+		ops:       typedOps,
+		pool:      pool,
+		vars:      vars,
+		stacksize: maxstack,
+		tailLen:   tailLen,
+		verb:      verb,
+	}, nil
+}
+
+// MustPattern is a helper function which makes it easier to call NewPattern in variable initialization.
+func MustPattern(p Pattern, err error) Pattern {
+	if err != nil {
+		grpclog.Fatalf("Pattern initialization failed: %v", err)
+	}
+	return p
+}
+
+// Match examines components if it matches to the Pattern.
+// If it matches, the function returns a mapping from field paths to their captured values.
+// If otherwise, the function returns an error.
+func (p Pattern) Match(components []string, verb string) (map[string]string, error) {
+	if p.verb != verb {
+		return nil, ErrNotMatch
+	}
+
+	var pos int
+	stack := make([]string, 0, p.stacksize)
+	captured := make([]string, len(p.vars))
+	l := len(components)
+	for _, op := range p.ops {
+		switch op.code {
+		case utilities.OpNop:
+			continue
+		case utilities.OpPush, utilities.OpLitPush:
+			if pos >= l {
+				return nil, ErrNotMatch
+			}
+			c := components[pos]
+			if op.code == utilities.OpLitPush {
+				if lit := p.pool[op.operand]; c != lit {
+					return nil, ErrNotMatch
+				}
+			}
+			stack = append(stack, c)
+			pos++
+		case utilities.OpPushM:
+			end := len(components)
+			if end < pos+p.tailLen {
+				return nil, ErrNotMatch
+			}
+			end -= p.tailLen
+			stack = append(stack, strings.Join(components[pos:end], "/"))
+			pos = end
+		case utilities.OpConcatN:
+			n := op.operand
+			l := len(stack) - n
+			stack = append(stack[:l], strings.Join(stack[l:], "/"))
+		case utilities.OpCapture:
+			n := len(stack) - 1
+			captured[op.operand] = stack[n]
+			stack = stack[:n]
+		}
+	}
+	if pos < l {
+		return nil, ErrNotMatch
+	}
+	bindings := make(map[string]string)
+	for i, val := range captured {
+		bindings[p.vars[i]] = val
+	}
+	return bindings, nil
+}
+
+// Verb returns the verb part of the Pattern.
+func (p Pattern) Verb() string { return p.verb }
+
+func (p Pattern) String() string {
+	var stack []string
+	for _, op := range p.ops {
+		switch op.code {
+		case utilities.OpNop:
+			continue
+		case utilities.OpPush:
+			stack = append(stack, "*")
+		case utilities.OpLitPush:
+			stack = append(stack, p.pool[op.operand])
+		case utilities.OpPushM:
+			stack = append(stack, "**")
+		case utilities.OpConcatN:
+			n := op.operand
+			l := len(stack) - n
+			stack = append(stack[:l], strings.Join(stack[l:], "/"))
+		case utilities.OpCapture:
+			n := len(stack) - 1
+			stack[n] = fmt.Sprintf("{%s=%s}", p.vars[op.operand], stack[n])
+		}
+	}
+	segs := strings.Join(stack, "/")
+	if p.verb != "" {
+		return fmt.Sprintf("/%s:%s", segs, p.verb)
+	}
+	return "/" + segs
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto2_convert.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto2_convert.go
new file mode 100644
index 0000000..a3151e2
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto2_convert.go
@@ -0,0 +1,80 @@
+package runtime
+
+import (
+	"github.com/golang/protobuf/proto"
+)
+
+// StringP returns a pointer to a string whose pointee is same as the given string value.
+func StringP(val string) (*string, error) {
+	return proto.String(val), nil
+}
+
+// BoolP parses the given string representation of a boolean value,
+// and returns a pointer to a bool whose value is same as the parsed value.
+func BoolP(val string) (*bool, error) {
+	b, err := Bool(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Bool(b), nil
+}
+
+// Float64P parses the given string representation of a floating point number,
+// and returns a pointer to a float64 whose value is same as the parsed number.
+func Float64P(val string) (*float64, error) {
+	f, err := Float64(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Float64(f), nil
+}
+
+// Float32P parses the given string representation of a floating point number,
+// and returns a pointer to a float32 whose value is same as the parsed number.
+func Float32P(val string) (*float32, error) {
+	f, err := Float32(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Float32(f), nil
+}
+
+// Int64P parses the given string representation of an integer
+// and returns a pointer to a int64 whose value is same as the parsed integer.
+func Int64P(val string) (*int64, error) {
+	i, err := Int64(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Int64(i), nil
+}
+
+// Int32P parses the given string representation of an integer
+// and returns a pointer to a int32 whose value is same as the parsed integer.
+func Int32P(val string) (*int32, error) {
+	i, err := Int32(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Int32(i), err
+}
+
+// Uint64P parses the given string representation of an integer
+// and returns a pointer to a uint64 whose value is same as the parsed integer.
+func Uint64P(val string) (*uint64, error) {
+	i, err := Uint64(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Uint64(i), err
+}
+
+// Uint32P parses the given string representation of an integer
+// and returns a pointer to a uint32 whose value is same as the parsed integer.
+func Uint32P(val string) (*uint32, error) {
+	i, err := Uint32(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Uint32(i), err
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto_errors.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto_errors.go
new file mode 100644
index 0000000..43fafca
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto_errors.go
@@ -0,0 +1,61 @@
+package runtime
+
+import (
+	"io"
+	"net/http"
+
+	"context"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+// ProtoErrorHandlerFunc handles the error as a gRPC error generated via status package and replies to the request.
+type ProtoErrorHandlerFunc func(context.Context, *ServeMux, Marshaler, http.ResponseWriter, *http.Request, error)
+
+var _ ProtoErrorHandlerFunc = DefaultHTTPProtoErrorHandler
+
+// DefaultHTTPProtoErrorHandler is an implementation of HTTPError.
+// If "err" is an error from gRPC system, the function replies with the status code mapped by HTTPStatusFromCode.
+// If otherwise, it replies with http.StatusInternalServerError.
+//
+// The response body returned by this function is a Status message marshaled by a Marshaler.
+//
+// Do not set this function to HTTPError variable directly, use WithProtoErrorHandler option instead.
+func DefaultHTTPProtoErrorHandler(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, _ *http.Request, err error) {
+	// return Internal when Marshal failed
+	const fallback = `{"code": 13, "message": "failed to marshal error message"}`
+
+	w.Header().Del("Trailer")
+	w.Header().Set("Content-Type", marshaler.ContentType())
+
+	s, ok := status.FromError(err)
+	if !ok {
+		s = status.New(codes.Unknown, err.Error())
+	}
+
+	buf, merr := marshaler.Marshal(s.Proto())
+	if merr != nil {
+		grpclog.Infof("Failed to marshal error message %q: %v", s.Proto(), merr)
+		w.WriteHeader(http.StatusInternalServerError)
+		if _, err := io.WriteString(w, fallback); err != nil {
+			grpclog.Infof("Failed to write response: %v", err)
+		}
+		return
+	}
+
+	md, ok := ServerMetadataFromContext(ctx)
+	if !ok {
+		grpclog.Infof("Failed to extract ServerMetadata from context")
+	}
+
+	handleForwardResponseServerMetadata(w, mux, md)
+	handleForwardResponseTrailerHeader(w, md)
+	st := HTTPStatusFromCode(s.Code())
+	w.WriteHeader(st)
+	if _, err := w.Write(buf); err != nil {
+		grpclog.Infof("Failed to write response: %v", err)
+	}
+
+	handleForwardResponseTrailer(w, md)
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/query.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/query.go
new file mode 100644
index 0000000..bb9359f
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/query.go
@@ -0,0 +1,392 @@
+package runtime
+
+import (
+	"encoding/base64"
+	"fmt"
+	"net/url"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/grpc-ecosystem/grpc-gateway/utilities"
+	"google.golang.org/grpc/grpclog"
+)
+
+// PopulateQueryParameters populates "values" into "msg".
+// A value is ignored if its key starts with one of the elements in "filter".
+func PopulateQueryParameters(msg proto.Message, values url.Values, filter *utilities.DoubleArray) error {
+	for key, values := range values {
+		re, err := regexp.Compile("^(.*)\\[(.*)\\]$")
+		if err != nil {
+			return err
+		}
+		match := re.FindStringSubmatch(key)
+		if len(match) == 3 {
+			key = match[1]
+			values = append([]string{match[2]}, values...)
+		}
+		fieldPath := strings.Split(key, ".")
+		if filter.HasCommonPrefix(fieldPath) {
+			continue
+		}
+		if err := populateFieldValueFromPath(msg, fieldPath, values); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// PopulateFieldFromPath sets a value in a nested Protobuf structure.
+// It instantiates missing protobuf fields as it goes.
+func PopulateFieldFromPath(msg proto.Message, fieldPathString string, value string) error {
+	fieldPath := strings.Split(fieldPathString, ".")
+	return populateFieldValueFromPath(msg, fieldPath, []string{value})
+}
+
+func populateFieldValueFromPath(msg proto.Message, fieldPath []string, values []string) error {
+	m := reflect.ValueOf(msg)
+	if m.Kind() != reflect.Ptr {
+		return fmt.Errorf("unexpected type %T: %v", msg, msg)
+	}
+	var props *proto.Properties
+	m = m.Elem()
+	for i, fieldName := range fieldPath {
+		isLast := i == len(fieldPath)-1
+		if !isLast && m.Kind() != reflect.Struct {
+			return fmt.Errorf("non-aggregate type in the mid of path: %s", strings.Join(fieldPath, "."))
+		}
+		var f reflect.Value
+		var err error
+		f, props, err = fieldByProtoName(m, fieldName)
+		if err != nil {
+			return err
+		} else if !f.IsValid() {
+			grpclog.Infof("field not found in %T: %s", msg, strings.Join(fieldPath, "."))
+			return nil
+		}
+
+		switch f.Kind() {
+		case reflect.Bool, reflect.Float32, reflect.Float64, reflect.Int32, reflect.Int64, reflect.String, reflect.Uint32, reflect.Uint64:
+			if !isLast {
+				return fmt.Errorf("unexpected nested field %s in %s", fieldPath[i+1], strings.Join(fieldPath[:i+1], "."))
+			}
+			m = f
+		case reflect.Slice:
+			if !isLast {
+				return fmt.Errorf("unexpected repeated field in %s", strings.Join(fieldPath, "."))
+			}
+			// Handle []byte
+			if f.Type().Elem().Kind() == reflect.Uint8 {
+				m = f
+				break
+			}
+			return populateRepeatedField(f, values, props)
+		case reflect.Ptr:
+			if f.IsNil() {
+				m = reflect.New(f.Type().Elem())
+				f.Set(m.Convert(f.Type()))
+			}
+			m = f.Elem()
+			continue
+		case reflect.Struct:
+			m = f
+			continue
+		case reflect.Map:
+			if !isLast {
+				return fmt.Errorf("unexpected nested field %s in %s", fieldPath[i+1], strings.Join(fieldPath[:i+1], "."))
+			}
+			return populateMapField(f, values, props)
+		default:
+			return fmt.Errorf("unexpected type %s in %T", f.Type(), msg)
+		}
+	}
+	switch len(values) {
+	case 0:
+		return fmt.Errorf("no value of field: %s", strings.Join(fieldPath, "."))
+	case 1:
+	default:
+		grpclog.Infof("too many field values: %s", strings.Join(fieldPath, "."))
+	}
+	return populateField(m, values[0], props)
+}
+
+// fieldByProtoName looks up a field whose corresponding protobuf field name is "name".
+// "m" must be a struct value. It returns zero reflect.Value if no such field found.
+func fieldByProtoName(m reflect.Value, name string) (reflect.Value, *proto.Properties, error) {
+	props := proto.GetProperties(m.Type())
+
+	// look up field name in oneof map
+	if op, ok := props.OneofTypes[name]; ok {
+		v := reflect.New(op.Type.Elem())
+		field := m.Field(op.Field)
+		if !field.IsNil() {
+			return reflect.Value{}, nil, fmt.Errorf("field already set for %s oneof", props.Prop[op.Field].OrigName)
+		}
+		field.Set(v)
+		return v.Elem().Field(0), op.Prop, nil
+	}
+
+	for _, p := range props.Prop {
+		if p.OrigName == name {
+			return m.FieldByName(p.Name), p, nil
+		}
+		if p.JSONName == name {
+			return m.FieldByName(p.Name), p, nil
+		}
+	}
+	return reflect.Value{}, nil, nil
+}
+
+func populateMapField(f reflect.Value, values []string, props *proto.Properties) error {
+	if len(values) != 2 {
+		return fmt.Errorf("more than one value provided for key %s in map %s", values[0], props.Name)
+	}
+
+	key, value := values[0], values[1]
+	keyType := f.Type().Key()
+	valueType := f.Type().Elem()
+	if f.IsNil() {
+		f.Set(reflect.MakeMap(f.Type()))
+	}
+
+	keyConv, ok := convFromType[keyType.Kind()]
+	if !ok {
+		return fmt.Errorf("unsupported key type %s in map %s", keyType, props.Name)
+	}
+	valueConv, ok := convFromType[valueType.Kind()]
+	if !ok {
+		return fmt.Errorf("unsupported value type %s in map %s", valueType, props.Name)
+	}
+
+	keyV := keyConv.Call([]reflect.Value{reflect.ValueOf(key)})
+	if err := keyV[1].Interface(); err != nil {
+		return err.(error)
+	}
+	valueV := valueConv.Call([]reflect.Value{reflect.ValueOf(value)})
+	if err := valueV[1].Interface(); err != nil {
+		return err.(error)
+	}
+
+	f.SetMapIndex(keyV[0].Convert(keyType), valueV[0].Convert(valueType))
+
+	return nil
+}
+
+func populateRepeatedField(f reflect.Value, values []string, props *proto.Properties) error {
+	elemType := f.Type().Elem()
+
+	// is the destination field a slice of an enumeration type?
+	if enumValMap := proto.EnumValueMap(props.Enum); enumValMap != nil {
+		return populateFieldEnumRepeated(f, values, enumValMap)
+	}
+
+	conv, ok := convFromType[elemType.Kind()]
+	if !ok {
+		return fmt.Errorf("unsupported field type %s", elemType)
+	}
+	f.Set(reflect.MakeSlice(f.Type(), len(values), len(values)).Convert(f.Type()))
+	for i, v := range values {
+		result := conv.Call([]reflect.Value{reflect.ValueOf(v)})
+		if err := result[1].Interface(); err != nil {
+			return err.(error)
+		}
+		f.Index(i).Set(result[0].Convert(f.Index(i).Type()))
+	}
+	return nil
+}
+
+func populateField(f reflect.Value, value string, props *proto.Properties) error {
+	i := f.Addr().Interface()
+
+	// Handle protobuf well known types
+	type wkt interface {
+		XXX_WellKnownType() string
+	}
+	if wkt, ok := i.(wkt); ok {
+		switch wkt.XXX_WellKnownType() {
+		case "Timestamp":
+			if value == "null" {
+				f.Field(0).SetInt(0)
+				f.Field(1).SetInt(0)
+				return nil
+			}
+
+			t, err := time.Parse(time.RFC3339Nano, value)
+			if err != nil {
+				return fmt.Errorf("bad Timestamp: %v", err)
+			}
+			f.Field(0).SetInt(int64(t.Unix()))
+			f.Field(1).SetInt(int64(t.Nanosecond()))
+			return nil
+		case "Duration":
+			if value == "null" {
+				f.Field(0).SetInt(0)
+				f.Field(1).SetInt(0)
+				return nil
+			}
+			d, err := time.ParseDuration(value)
+			if err != nil {
+				return fmt.Errorf("bad Duration: %v", err)
+			}
+
+			ns := d.Nanoseconds()
+			s := ns / 1e9
+			ns %= 1e9
+			f.Field(0).SetInt(s)
+			f.Field(1).SetInt(ns)
+			return nil
+		case "DoubleValue":
+			fallthrough
+		case "FloatValue":
+			float64Val, err := strconv.ParseFloat(value, 64)
+			if err != nil {
+				return fmt.Errorf("bad DoubleValue: %s", value)
+			}
+			f.Field(0).SetFloat(float64Val)
+			return nil
+		case "Int64Value":
+			fallthrough
+		case "Int32Value":
+			int64Val, err := strconv.ParseInt(value, 10, 64)
+			if err != nil {
+				return fmt.Errorf("bad DoubleValue: %s", value)
+			}
+			f.Field(0).SetInt(int64Val)
+			return nil
+		case "UInt64Value":
+			fallthrough
+		case "UInt32Value":
+			uint64Val, err := strconv.ParseUint(value, 10, 64)
+			if err != nil {
+				return fmt.Errorf("bad DoubleValue: %s", value)
+			}
+			f.Field(0).SetUint(uint64Val)
+			return nil
+		case "BoolValue":
+			if value == "true" {
+				f.Field(0).SetBool(true)
+			} else if value == "false" {
+				f.Field(0).SetBool(false)
+			} else {
+				return fmt.Errorf("bad BoolValue: %s", value)
+			}
+			return nil
+		case "StringValue":
+			f.Field(0).SetString(value)
+			return nil
+		case "BytesValue":
+			bytesVal, err := base64.StdEncoding.DecodeString(value)
+			if err != nil {
+				return fmt.Errorf("bad BytesValue: %s", value)
+			}
+			f.Field(0).SetBytes(bytesVal)
+			return nil
+		}
+	}
+
+	// Handle google well known types
+	if gwkt, ok := i.(proto.Message); ok {
+		switch proto.MessageName(gwkt) {
+		case "google.protobuf.FieldMask":
+			p := f.Field(0)
+			for _, v := range strings.Split(value, ",") {
+				if v != "" {
+					p.Set(reflect.Append(p, reflect.ValueOf(v)))
+				}
+			}
+			return nil
+		}
+	}
+
+	// Handle Time and Duration stdlib types
+	switch t := i.(type) {
+	case *time.Time:
+		pt, err := time.Parse(time.RFC3339Nano, value)
+		if err != nil {
+			return fmt.Errorf("bad Timestamp: %v", err)
+		}
+		*t = pt
+		return nil
+	case *time.Duration:
+		d, err := time.ParseDuration(value)
+		if err != nil {
+			return fmt.Errorf("bad Duration: %v", err)
+		}
+		*t = d
+		return nil
+	}
+
+	// is the destination field an enumeration type?
+	if enumValMap := proto.EnumValueMap(props.Enum); enumValMap != nil {
+		return populateFieldEnum(f, value, enumValMap)
+	}
+
+	conv, ok := convFromType[f.Kind()]
+	if !ok {
+		return fmt.Errorf("field type %T is not supported in query parameters", i)
+	}
+	result := conv.Call([]reflect.Value{reflect.ValueOf(value)})
+	if err := result[1].Interface(); err != nil {
+		return err.(error)
+	}
+	f.Set(result[0].Convert(f.Type()))
+	return nil
+}
+
+func convertEnum(value string, t reflect.Type, enumValMap map[string]int32) (reflect.Value, error) {
+	// see if it's an enumeration string
+	if enumVal, ok := enumValMap[value]; ok {
+		return reflect.ValueOf(enumVal).Convert(t), nil
+	}
+
+	// check for an integer that matches an enumeration value
+	eVal, err := strconv.Atoi(value)
+	if err != nil {
+		return reflect.Value{}, fmt.Errorf("%s is not a valid %s", value, t)
+	}
+	for _, v := range enumValMap {
+		if v == int32(eVal) {
+			return reflect.ValueOf(eVal).Convert(t), nil
+		}
+	}
+	return reflect.Value{}, fmt.Errorf("%s is not a valid %s", value, t)
+}
+
+func populateFieldEnum(f reflect.Value, value string, enumValMap map[string]int32) error {
+	cval, err := convertEnum(value, f.Type(), enumValMap)
+	if err != nil {
+		return err
+	}
+	f.Set(cval)
+	return nil
+}
+
+func populateFieldEnumRepeated(f reflect.Value, values []string, enumValMap map[string]int32) error {
+	elemType := f.Type().Elem()
+	f.Set(reflect.MakeSlice(f.Type(), len(values), len(values)).Convert(f.Type()))
+	for i, v := range values {
+		result, err := convertEnum(v, elemType, enumValMap)
+		if err != nil {
+			return err
+		}
+		f.Index(i).Set(result)
+	}
+	return nil
+}
+
+var (
+	convFromType = map[reflect.Kind]reflect.Value{
+		reflect.String:  reflect.ValueOf(String),
+		reflect.Bool:    reflect.ValueOf(Bool),
+		reflect.Float64: reflect.ValueOf(Float64),
+		reflect.Float32: reflect.ValueOf(Float32),
+		reflect.Int64:   reflect.ValueOf(Int64),
+		reflect.Int32:   reflect.ValueOf(Int32),
+		reflect.Uint64:  reflect.ValueOf(Uint64),
+		reflect.Uint32:  reflect.ValueOf(Uint32),
+		reflect.Slice:   reflect.ValueOf(Bytes),
+	}
+)
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis/LICENSE b/vendor/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis/LICENSE
new file mode 100644
index 0000000..261eeb9
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
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+
+   Unless required by applicable law or agreed to in writing, software
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diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/BUILD.bazel b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/BUILD.bazel
new file mode 100644
index 0000000..58d291c
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/BUILD.bazel
@@ -0,0 +1,20 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+package(default_visibility = ["//visibility:public"])
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "doc.go",
+        "pattern.go",
+        "trie.go",
+    ],
+    importpath = "github.com/grpc-ecosystem/grpc-gateway/utilities",
+)
+
+go_test(
+    name = "go_default_xtest",
+    size = "small",
+    srcs = ["trie_test.go"],
+    deps = [":go_default_library"],
+)
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/doc.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/doc.go
new file mode 100644
index 0000000..cf79a4d
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/doc.go
@@ -0,0 +1,2 @@
+// Package utilities provides members for internal use in grpc-gateway.
+package utilities
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/pattern.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/pattern.go
new file mode 100644
index 0000000..dfe7de4
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/pattern.go
@@ -0,0 +1,22 @@
+package utilities
+
+// An OpCode is a opcode of compiled path patterns.
+type OpCode int
+
+// These constants are the valid values of OpCode.
+const (
+	// OpNop does nothing
+	OpNop = OpCode(iota)
+	// OpPush pushes a component to stack
+	OpPush
+	// OpLitPush pushes a component to stack if it matches to the literal
+	OpLitPush
+	// OpPushM concatenates the remaining components and pushes it to stack
+	OpPushM
+	// OpConcatN pops N items from stack, concatenates them and pushes it back to stack
+	OpConcatN
+	// OpCapture pops an item and binds it to the variable
+	OpCapture
+	// OpEnd is the least positive invalid opcode.
+	OpEnd
+)
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/trie.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/trie.go
new file mode 100644
index 0000000..c2b7b30
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/trie.go
@@ -0,0 +1,177 @@
+package utilities
+
+import (
+	"sort"
+)
+
+// DoubleArray is a Double Array implementation of trie on sequences of strings.
+type DoubleArray struct {
+	// Encoding keeps an encoding from string to int
+	Encoding map[string]int
+	// Base is the base array of Double Array
+	Base []int
+	// Check is the check array of Double Array
+	Check []int
+}
+
+// NewDoubleArray builds a DoubleArray from a set of sequences of strings.
+func NewDoubleArray(seqs [][]string) *DoubleArray {
+	da := &DoubleArray{Encoding: make(map[string]int)}
+	if len(seqs) == 0 {
+		return da
+	}
+
+	encoded := registerTokens(da, seqs)
+	sort.Sort(byLex(encoded))
+
+	root := node{row: -1, col: -1, left: 0, right: len(encoded)}
+	addSeqs(da, encoded, 0, root)
+
+	for i := len(da.Base); i > 0; i-- {
+		if da.Check[i-1] != 0 {
+			da.Base = da.Base[:i]
+			da.Check = da.Check[:i]
+			break
+		}
+	}
+	return da
+}
+
+func registerTokens(da *DoubleArray, seqs [][]string) [][]int {
+	var result [][]int
+	for _, seq := range seqs {
+		var encoded []int
+		for _, token := range seq {
+			if _, ok := da.Encoding[token]; !ok {
+				da.Encoding[token] = len(da.Encoding)
+			}
+			encoded = append(encoded, da.Encoding[token])
+		}
+		result = append(result, encoded)
+	}
+	for i := range result {
+		result[i] = append(result[i], len(da.Encoding))
+	}
+	return result
+}
+
+type node struct {
+	row, col    int
+	left, right int
+}
+
+func (n node) value(seqs [][]int) int {
+	return seqs[n.row][n.col]
+}
+
+func (n node) children(seqs [][]int) []*node {
+	var result []*node
+	lastVal := int(-1)
+	last := new(node)
+	for i := n.left; i < n.right; i++ {
+		if lastVal == seqs[i][n.col+1] {
+			continue
+		}
+		last.right = i
+		last = &node{
+			row:  i,
+			col:  n.col + 1,
+			left: i,
+		}
+		result = append(result, last)
+	}
+	last.right = n.right
+	return result
+}
+
+func addSeqs(da *DoubleArray, seqs [][]int, pos int, n node) {
+	ensureSize(da, pos)
+
+	children := n.children(seqs)
+	var i int
+	for i = 1; ; i++ {
+		ok := func() bool {
+			for _, child := range children {
+				code := child.value(seqs)
+				j := i + code
+				ensureSize(da, j)
+				if da.Check[j] != 0 {
+					return false
+				}
+			}
+			return true
+		}()
+		if ok {
+			break
+		}
+	}
+	da.Base[pos] = i
+	for _, child := range children {
+		code := child.value(seqs)
+		j := i + code
+		da.Check[j] = pos + 1
+	}
+	terminator := len(da.Encoding)
+	for _, child := range children {
+		code := child.value(seqs)
+		if code == terminator {
+			continue
+		}
+		j := i + code
+		addSeqs(da, seqs, j, *child)
+	}
+}
+
+func ensureSize(da *DoubleArray, i int) {
+	for i >= len(da.Base) {
+		da.Base = append(da.Base, make([]int, len(da.Base)+1)...)
+		da.Check = append(da.Check, make([]int, len(da.Check)+1)...)
+	}
+}
+
+type byLex [][]int
+
+func (l byLex) Len() int      { return len(l) }
+func (l byLex) Swap(i, j int) { l[i], l[j] = l[j], l[i] }
+func (l byLex) Less(i, j int) bool {
+	si := l[i]
+	sj := l[j]
+	var k int
+	for k = 0; k < len(si) && k < len(sj); k++ {
+		if si[k] < sj[k] {
+			return true
+		}
+		if si[k] > sj[k] {
+			return false
+		}
+	}
+	if k < len(sj) {
+		return true
+	}
+	return false
+}
+
+// HasCommonPrefix determines if any sequence in the DoubleArray is a prefix of the given sequence.
+func (da *DoubleArray) HasCommonPrefix(seq []string) bool {
+	if len(da.Base) == 0 {
+		return false
+	}
+
+	var i int
+	for _, t := range seq {
+		code, ok := da.Encoding[t]
+		if !ok {
+			break
+		}
+		j := da.Base[i] + code
+		if len(da.Check) <= j || da.Check[j] != i+1 {
+			break
+		}
+		i = j
+	}
+	j := da.Base[i] + len(da.Encoding)
+	if len(da.Check) <= j || da.Check[j] != i+1 {
+		return false
+	}
+	return true
+}