Remove old comment referencing the project name

It was obvious which project the comment was about. Also, no point
having a TODO referencing what to do after upgrading to Rails 5.1, since
we did it years ago.

app/assets/javascripts/dashboard_graphs.js

@@ -2,8 +2,6 @@
 //= require c3
 //= require c3ext
 
-// TODO: This module is complex enough to require its own tests. Rewrite it using Ecma6 class syntax and
-// write tests for this feature after consul has been migrated to Rails 5.1
 (function() {
   "use strict";