Rename repo_file_buttons exported class

app/assets/javascripts/repo/repo_file_buttons.js

@@ -3,7 +3,7 @@ import Store from './repo_store';
 import Helper from './repo_helper';
 import RepoMiniMixin from './repo_mini_mixin';
 
-export default class RepoSidebar {
+export default class RepoFileButtons {
   constructor(url) {
     this.url = url;
     this.initVue();