update to higlight.js 8.4

vendor/assets/javascripts/highlight_js/languages/go.js

@@ -3,6 +3,7 @@ Language: Go
 Author: Stephan Kountso aka StepLg <steplg@gmail.com>
 Contributors: Evgeny Stepanischev <imbolk@gmail.com>
 Description: Google go language (golang). For info about language see http://golang.org/
+Category: system
 */
 
 function(hljs) {
@@ -36,7 +37,7 @@ function(hljs) {
       },
       {
         className: 'number',
-        begin: '[^a-zA-Z_0-9](\\-|\\+)?\\d+(\\.\\d+|\\/\\d+)?((d|e|f|l|s)(\\+|\\-)?\\d+)?',
+        begin: hljs.C_NUMBER_RE + '[dflsi]?',
         relevance: 0
       },
       hljs.C_NUMBER_MODE