Adds polyfill for CustomEvent

## What does this MR do?
CustomEvent is not supported by IE.- https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent

In order to stop using jQuery in new files that need to listen to custom events we need this polyfill.

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

See merge request !7705

Fix BASH usage in the .gitlab-ci.yml

As discussed on Slack. Even though I created the fix, I was a mere code monkey in this case.

See merge request !7693

API: Add endpoint to delete a group share

Closes #24771

See merge request !7662

add details that Git LFS must be enabled in project

## What does this MR do?

Add details that Git LFS must be enabled in project before it will work

See merge request !7680

Grapify the sidekiq metrics API

Related to #22928

See merge request !7699

Add support of Chrome/Chromium in requirements.md

See merge request !7703

[ci skip]

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/24863

See merge request !7698

Add a starting date to milestones

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/23704

See merge request !7484

post_receive: accept any user email from last commit

See merge request !7225

Use authorized projects in ProjectTeam

Closes #23938 and #23636

See merge request !7586

Ensure we sanitize branch names with path-unfriendly characters

See merge request !7696

Closes #23938

So that it matches the same access given in
Projects::CreateService#after_create_actions

Use the minimum access level of group link and group member when inserting authorized project records

Remove empty describe block in service spec

See merge request !7669

Notify broken master on #development

See merge request !7593

Edit help text to clarify that tags are annotated.

Closes #24554

See merge request !7553

Fix cycle analytics plan stage when commits are missing

Takes into account when commits are `nil` so the app doesn't throw an exception and also removes them.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/24836

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)


See merge request !7694

Signed-off-by: Rémy Coutable <remy@rymai.me>

Fix spacing between icon and word in status badge

Before:      
![Screen_Shot_2016-11-22_at_11.44.16_AM](/uploads/65c5abc6dc08985cb3079b7c2af03715/Screen_Shot_2016-11-22_at_11.44.16_AM.png)
After:   
![Screen_Shot_2016-11-22_at_11.44.01_AM](/uploads/1b6261b64c65de5a718b68873e069ac9/Screen_Shot_2016-11-22_at_11.44.01_AM.png)

cc @dimitrieh

See merge request !7678

Generate ESLint HTML report

## What does this MR do?

Generate a HTML report for the linting errors that ESLint discovered
(including files that contain `/* eslint-disable */`).

See merge request !7374