highlight arrow functions similar to functions

node_modules/ace/lib/ace/mode/javascript_highlight_rules.js

@@ -171,6 +171,9 @@ var JavaScriptHighlightRules = function(options) {
                 token : "punctuation.operator",
                 regex : /[.](?![.])/,
                 next  : "property"
+            }, {
+                token : "storage.type",
+                regex : /=>/
             }, {
                 token : "keyword.operator",
                 regex : /--|\+\+|\.{3}|===|==|=|!=|!==|<+=?|>+=?|!|&&|\|\||\?\:|[!$%&*+\-~\/^]=?/,