[Rails5] Add `rails-controller-testing` gem

See merge request gitlab-org/gitlab-ce!18242

Fix undefined method `one?` when pushing to an existing merge request

Closes #45152

See merge request gitlab-org/gitlab-ce!18243

Remove modal boards code from global namepsace

See merge request gitlab-org/gitlab-ce!18222

[Rails5] Add FALSE_VALUES constant to Service#boolean_accessor

See merge request gitlab-org/gitlab-ce!18240

Resolve "Template selectors menu title mistakenly shown after toggling previewed changes"

Closes #32617

See merge request gitlab-org/gitlab-ce!18118

Handle legacy repository archive requests with no ref given

Closes #45154

See merge request gitlab-org/gitlab-ce!18246

The legacy endpoint requires no reference and defaults to the root
ref.

Closes #45154

Add user documentation for badges

Closes #41174 and #41176

See merge request gitlab-org/gitlab-ce!18200

Projects and groups badges settings UI

Closes #41174 and #41176

See merge request gitlab-org/gitlab-ce!17114

An untested code path was triggering an Exception because Fixnum
doesn't have `one?` implemented in Rails, while arrays and collections
do.

Closes #45152

In Rails 5.0 `assert_template` and `assigns()` have been extracted to
the `rails-controller-testing` gem.
https://github.com/rails/rails/pull/20138/files

This commit adds this gem for rails5.

In Rails 5.0 the `ActiveRecord::ConnectionAdapters::Column::TRUE_VALUES`
constant has been removed [1] and the remaining `FALSE_VALUES` constant
has been moved to `ActiveModel::Type::Boolean` [2]

[1]: https://github.com/rails/rails/commit/a502703c3d2151d4d3b421b29fefdac5ad05df61
[2]: https://github.com/rails/rails/commit/9cc8c6f3730df3d94c81a55be9ee1b7b4ffd29f6

Create Project Deploy Tokens to allow permanent access to repo and registry

Closes #31591

See merge request gitlab-org/gitlab-ce!17894

Bump `parser` gem to 2.5.0.5

See merge request gitlab-org/gitlab-ce!18237

The TIMESTAMP data type is used for values that contain both date and
time parts. TIMESTAMP has a range of '1970-01-01 00:00:01' UTC to
'2038-01-19 03:14:07' UTC.

A Forever lib class was included to handle future dates for PostgreSQL
and MySQL, also changes were made to DeployToken to enforce Forever.date

Also removes extra conditional from JwtController

- Adds a default on expires_at datetime
- Modifies deploy tokens views to handle default expires at value
- Use datetime_with_timezone where possible
- Remove unused scopes

Also, fixes broken specs

We use controller actions to pass a newly created token and errors

Also:
- Changes scopes from serializer to use boolean columns
- Fixes broken specs

- Remove extra method for authorize_admin_project
- Ensure project presence
- Rename 'read_repo' to 'read_repository' to be more verbose

- When using 'read_repo' password and project are sent, so we used both
  of them to fetch for the token
- When using 'read_registry' only the password is sent, so we only use
  that for fetching the token

Also fixes spec failures on presenter and docs

- Keep 'Deploy Section' open upon save, otherwise the token might get
  lost
- When an error appears, display the error inside the form and also keep
  the Deploy Section open
- Changue copy of revoke modal

This will allow to download a repo using the token from the DeployToken

Includes:
- Model, factories, create service and controller actions
- As usual, includes specs for everything
- Builds UI (copy from PAT)
- Add revoke action

Closes #31591

1. Synchronize used version of `parser` gem for both versions of rails: 4 and 5.
2. Fix broken CI pipelines for rails5 branches.

The 2.5.0.4 version is removed from rubygems, so it's skipped.
https://github.com/whitequark/parser/issues/478