Adds tests.
Changes instance into a constructor

Adds tests for environments component

Adds tests assertations

Adds external URL test

Adds tests for Rollback component

Adds tests for stop component

Adds tests for actions component
Fix environment item

Init environment item tests

Adds commit component

Fixes some tests

Steps to reproduce:

1. Start with a repo with an image
2. Add a commit to delete the image
3. Add another commit to replace the image with another image

In a diff comparison, we really just compare about what the image was before the diff, not
the direct parent of the last commit. This MR fixes that.

Closes #3893, gitlab-org/gitlab-ee#678
Signed-off-by: NRémy Coutable <remy@rymai.me>

Added ability to put emojis into repository name

- Also remove unnecessary param

Centralize all LDAP config logic in `GitLab::LDAP::Config`. Previously,
some logic was in the Devise initializer and it was not honoring the
`user_filter`. If a user outside the configured `user_filter` signed
in, an account would be created but they would then be denied access.
Now that logic is centralized, the filter is honored and users outside
the filter are never created.

See https://gitlab.com/gitlab-org/gitlab-ce/issues/24386

Previously, they were only being loaded on the actual `show` action, but
not the actions representing the tabs (commits, builds, etc).

In this case comparing old_path and new_path is not enough because there
are two entires that match.