Navigation bar links get underline style when active

Screen_Shot_2018-06-20_at_13.00.50

From slack:

    text-decoration: underline;
}```
in app/assets/stylesheets/bootstrap_migration.scss

the culprit code. so it's on all links that are not buttons and also happens when you focus.

Might need some exclusions there.. sidebar, webide, etc.

https://gitlab.com/gitlab-org/gitlab-ee/commit/37bd3d44c6c985fc6e2a61488aadd31b01f36eb0