Ci Project migrate
- This doesn't migrate: allow_git_fetch, coverage_regex, timeout. Since this are project configuration settings I would propose to migrate them to `.gitlab-ci.yml`.
- This requires offline migrations.
- It simplifies database models making all CI objects to be attached to: Project.
- It removes Ci::Project, but makes /ci/projects working by adding method: Project.find_by_ci_id for backward compatibility (badges, triggers).
- We should add default `timeout` to Application Settings.
- It misses specs.
- It is based on ci-services-migrate for now.
- It removes CI events.
- It removes administrator CI projects overview.
- It removes CI application settings.
In 8.4 or 8.5 we can remove redundant tables and columns.
See merge request !1987
Add Builds tab to MR detail page
## Before

## After

Fixes#3907
See merge request !2016
Build related UI fixes
## Before

## After

See merge request !2015
Fix problems with award-emoji-only comment
This fixes a conflict between note with only a single emoji in content
and award-emojis mechanisms.
Closes#3734
cc @vsizov
See merge request !1936
If a Web hook test fails due to an SSL error or some other error, report
the result back to the user instead of an Error 500.
Closes#3656
Handle response
Award Emoji
This it first iteration of award emoji feature.
We have plan to extend emoji picker by the next release.
For now, you can add award by clicking to the emoji picker or posting a regular comment with emoji like "👍" and any other. You can post not only emoji that listed in the emoji picker.
See merge request !1825