fix eslint violations

app/assets/javascripts/lib/utils/datetime_utility.js

-/* eslint-disable func-names, space-before-function-paren, wrap-iife, no-var, no-param-reassign, no-cond-assign, comma-dangle, no-unused-expressions, prefer-template, padded-blocks, max-len */
+/* eslint-disable func-names, space-before-function-paren, wrap-iife, no-var, no-param-reassign, no-cond-assign, comma-dangle, no-unused-expressions, prefer-template, prefer-arrow-callback, padded-blocks, max-len */
 /* global timeago */
 /* global dateFormat */
 
@@ -27,7 +27,7 @@
       });
 
       return new Date(dateArray[0], dateArray[1] - 1, dateArray[2]);
-    }
+    };
 
     w.gl.utils.formatDate = function(datetime) {
       return dateFormat(datetime, 'mmm d, yyyy h:MMtt Z');