Update dependencies

Closes #2129

vendor/github.com/russross/blackfriday/html.go

@@ -255,33 +255,21 @@ func (options *Html) HRule(out *bytes.Buffer) {
 	out.WriteByte('\n')
 }
 
-func (options *Html) BlockCode(out *bytes.Buffer, text []byte, lang string) {
+func (options *Html) BlockCode(out *bytes.Buffer, text []byte, info string) {
 	doubleSpace(out)
 
-	// parse out the language names/classes
-	count := 0
-	for _, elt := range strings.Fields(lang) {
-		if elt[0] == '.' {
-			elt = elt[1:]
-		}
-		if len(elt) == 0 {
-			continue
-		}
-		if count == 0 {
-			out.WriteString("<pre><code class=\"language-")
-		} else {
-			out.WriteByte(' ')
-		}
-		attrEscape(out, []byte(elt))
-		count++
+	endOfLang := strings.IndexAny(info, "\t ")
+	if endOfLang < 0 {
+		endOfLang = len(info)
 	}
-
-	if count == 0 {
+	lang := info[:endOfLang]
+	if len(lang) == 0 || lang == "." {
 		out.WriteString("<pre><code>")
 	} else {
+		out.WriteString("<pre><code class=\"language-")
+		attrEscape(out, []byte(lang))
 		out.WriteString("\">")
 	}
-
 	attrEscape(out, text)
 	out.WriteString("</code></pre>\n")
 }