diff --git a/unum/vendor/golang.org/x/net/html/doctype.go b/unum/vendor/golang.org/x/net/html/doctype.go
new file mode 100644
index 0000000..c484e5a
--- /dev/null
+++ b/unum/vendor/golang.org/x/net/html/doctype.go
@@ -0,0 +1,156 @@
+// Copyright 2011 The Go 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 html
+
+import (
+	"strings"
+)
+
+// parseDoctype parses the data from a DoctypeToken into a name,
+// public identifier, and system identifier. It returns a Node whose Type
+// is DoctypeNode, whose Data is the name, and which has attributes
+// named "system" and "public" for the two identifiers if they were present.
+// quirks is whether the document should be parsed in "quirks mode".
+func parseDoctype(s string) (n *Node, quirks bool) {
+	n = &Node{Type: DoctypeNode}
+
+	// Find the name.
+	space := strings.IndexAny(s, whitespace)
+	if space == -1 {
+		space = len(s)
+	}
+	n.Data = s[:space]
+	// The comparison to "html" is case-sensitive.
+	if n.Data != "html" {
+		quirks = true
+	}
+	n.Data = strings.ToLower(n.Data)
+	s = strings.TrimLeft(s[space:], whitespace)
+
+	if len(s) < 6 {
+		// It can't start with "PUBLIC" or "SYSTEM".
+		// Ignore the rest of the string.
+		return n, quirks || s != ""
+	}
+
+	key := strings.ToLower(s[:6])
+	s = s[6:]
+	for key == "public" || key == "system" {
+		s = strings.TrimLeft(s, whitespace)
+		if s == "" {
+			break
+		}
+		quote := s[0]
+		if quote != '"' && quote != '\'' {
+			break
+		}
+		s = s[1:]
+		q := strings.IndexRune(s, rune(quote))
+		var id string
+		if q == -1 {
+			id = s
+			s = ""
+		} else {
+			id = s[:q]
+			s = s[q+1:]
+		}
+		n.Attr = append(n.Attr, Attribute{Key: key, Val: id})
+		if key == "public" {
+			key = "system"
+		} else {
+			key = ""
+		}
+	}
+
+	if key != "" || s != "" {
+		quirks = true
+	} else if len(n.Attr) > 0 {
+		if n.Attr[0].Key == "public" {
+			public := strings.ToLower(n.Attr[0].Val)
+			switch public {
+			case "-//w3o//dtd w3 html strict 3.0//en//", "-/w3d/dtd html 4.0 transitional/en", "html":
+				quirks = true
+			default:
+				for _, q := range quirkyIDs {
+					if strings.HasPrefix(public, q) {
+						quirks = true
+						break
+					}
+				}
+			}
+			// The following two public IDs only cause quirks mode if there is no system ID.
+			if len(n.Attr) == 1 && (strings.HasPrefix(public, "-//w3c//dtd html 4.01 frameset//") ||
+				strings.HasPrefix(public, "-//w3c//dtd html 4.01 transitional//")) {
+				quirks = true
+			}
+		}
+		if lastAttr := n.Attr[len(n.Attr)-1]; lastAttr.Key == "system" &&
+			strings.ToLower(lastAttr.Val) == "http://www.ibm.com/data/dtd/v11/ibmxhtml1-transitional.dtd" {
+			quirks = true
+		}
+	}
+
+	return n, quirks
+}
+
+// quirkyIDs is a list of public doctype identifiers that cause a document
+// to be interpreted in quirks mode. The identifiers should be in lower case.
+var quirkyIDs = []string{
+	"+//silmaril//dtd html pro v0r11 19970101//",
+	"-//advasoft ltd//dtd html 3.0 aswedit + extensions//",
+	"-//as//dtd html 3.0 aswedit + extensions//",
+	"-//ietf//dtd html 2.0 level 1//",
+	"-//ietf//dtd html 2.0 level 2//",
+	"-//ietf//dtd html 2.0 strict level 1//",
+	"-//ietf//dtd html 2.0 strict level 2//",
+	"-//ietf//dtd html 2.0 strict//",
+	"-//ietf//dtd html 2.0//",
+	"-//ietf//dtd html 2.1e//",
+	"-//ietf//dtd html 3.0//",
+	"-//ietf//dtd html 3.2 final//",
+	"-//ietf//dtd html 3.2//",
+	"-//ietf//dtd html 3//",
+	"-//ietf//dtd html level 0//",
+	"-//ietf//dtd html level 1//",
+	"-//ietf//dtd html level 2//",
+	"-//ietf//dtd html level 3//",
+	"-//ietf//dtd html strict level 0//",
+	"-//ietf//dtd html strict level 1//",
+	"-//ietf//dtd html strict level 2//",
+	"-//ietf//dtd html strict level 3//",
+	"-//ietf//dtd html strict//",
+	"-//ietf//dtd html//",
+	"-//metrius//dtd metrius presentational//",
+	"-//microsoft//dtd internet explorer 2.0 html strict//",
+	"-//microsoft//dtd internet explorer 2.0 html//",
+	"-//microsoft//dtd internet explorer 2.0 tables//",
+	"-//microsoft//dtd internet explorer 3.0 html strict//",
+	"-//microsoft//dtd internet explorer 3.0 html//",
+	"-//microsoft//dtd internet explorer 3.0 tables//",
+	"-//netscape comm. corp.//dtd html//",
+	"-//netscape comm. corp.//dtd strict html//",
+	"-//o'reilly and associates//dtd html 2.0//",
+	"-//o'reilly and associates//dtd html extended 1.0//",
+	"-//o'reilly and associates//dtd html extended relaxed 1.0//",
+	"-//softquad software//dtd hotmetal pro 6.0::19990601::extensions to html 4.0//",
+	"-//softquad//dtd hotmetal pro 4.0::19971010::extensions to html 4.0//",
+	"-//spyglass//dtd html 2.0 extended//",
+	"-//sq//dtd html 2.0 hotmetal + extensions//",
+	"-//sun microsystems corp.//dtd hotjava html//",
+	"-//sun microsystems corp.//dtd hotjava strict html//",
+	"-//w3c//dtd html 3 1995-03-24//",
+	"-//w3c//dtd html 3.2 draft//",
+	"-//w3c//dtd html 3.2 final//",
+	"-//w3c//dtd html 3.2//",
+	"-//w3c//dtd html 3.2s draft//",
+	"-//w3c//dtd html 4.0 frameset//",
+	"-//w3c//dtd html 4.0 transitional//",
+	"-//w3c//dtd html experimental 19960712//",
+	"-//w3c//dtd html experimental 970421//",
+	"-//w3c//dtd w3 html//",
+	"-//w3o//dtd w3 html 3.0//",
+	"-//webtechs//dtd mozilla html 2.0//",
+	"-//webtechs//dtd mozilla html//",
+}