Re-enable eslint in `commits.js` file
app/assets/javascripts/commits.js
has eslint disabled as a consequence of the conversion from Coffeescript into plain JS
Task:
- Re-enable eslint and fix the broken rules
Note: In similar refactors we've transformed it into an ES6 class: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15503/diffs