Remove duplicate Vue scripts.

app/assets/javascripts/diff_notes/diff_notes_bundle.js.es6

 /* eslint-disable */
+//= require vue
+//= require vue-resource
 //= require_directory ./models
 //= require_directory ./stores
 //= require_directory ./services

app/assets/javascripts/issuable/time_tracking/components/time_tracker.js.es6

-//= require vue
 (() => {
   gl.IssuableTimeTracker = Vue.component('issuable-time-tracker', {
     name: 'issuable-time-tracker',

app/assets/javascripts/subbable_resource.js.es6

-//= require vue
-//= require vue-resource
-
 (() => {
 /*
 *   SubbableResource can be extended to provide a pubsub-style service for one-off REST