Limit number of shown environments

## What does this MR do?

This MR limits in context of Merge Request a list of shown environments. Previously we would show all environments containing the SHA of the head commit of Merge Request. However, with introducing of dynamically created environments this lead to a cases that we would show multiple review apps, for different branches, because these branches would contain a new questioned commit.

This MR changes what environments we test against presence of the commit, to:
1. We look for environments with deployments to source_branch of source_project: used for deployments to per-branch environments,
2. We look for environments with deployments to target_branch of target_project: used for deployments to staging / production environments,
3. We look for environments with deployments for tags on target_project: used for staging / production environments.

## Why was this MR needed?

To improve a list of returned environments when we introduced ability to create dynamic environments for review apps:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6323

See merge request !6438

Fix new project button alignment

## What does this MR do?
Increases the width of the button/search container to fit all items at smaller screen width. The left side of the row can only have a max of two tabs (All Projects, Shared Projects), so everything can still fit on one line until they resize for mobile

## Why was this MR needed?
The `New project` button wrapped to next line at smaller screen width, breaking the layout

## Screenshots (if relevant)
![Screen_Shot_2016-09-09_at_11.44.27_AM](/uploads/a726208deec6623d9fb62db0a549bf38/Screen_Shot_2016-09-09_at_11.44.27_AM.png)
![Screen_Shot_2016-09-09_at_11.46.29_AM](/uploads/bd8dc911757b14c5fafc4d3849e0b242/Screen_Shot_2016-09-09_at_11.46.29_AM.png)

## What are the relevant issue numbers?
Closes #20310

See merge request !6286

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

See !6196.

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

Add spec covering 'committer_hash'

Adds a missing spec from changes added in !5822

See merge request !6433

Bump GITLAB_SHELL_VERSION to 3.6.0 for SSH support for LFS.

cc @rdavila

See merge request !6441

Post-merge improve of CI permissions

Improves code from !6409

See merge request !6432

- For target project show only environments for target branch or with tags
- For source project show only environments for source branch

Upgrade Sidekiq to 4.2.1, remove dependency on Sinatra

This updates Sidekiq to 4.2.1, which adds full support for Rails 5 by removing a dependency on Sinatra which was one of the remaining Rails 5 blockers.

Major things to check: Sidekiq still works, obviously. Also that the Web UI/Admin dashboard works and doesn't lose any functionality (based on my testing it works fine).

Working toward #14286.

Changelog: https://github.com/mperham/sidekiq/blob/921e939f995fbb5238975d4121d728b95be99ab5/Changes.md#421

See merge request !6349

Cycle Analytics: first iteration

## What does this MR do?

- Implement the first iteration of the "Cycle Analytics" feature.

## What are the relevant issue numbers?

- Closes #21170 

## Screenshots

![cycle_analytics_screencast.gif](/uploads/d23c3c912caa6935fd47b53ca3a56b97/cycle_analytics.gif)

## Backend Tasks

- [x]  Implementation
    - [x]  Phases
        - [x]  Issue (Tracker)
        - [x]  Plan (Board)
        - [x]  Code (IDE)
        - [x]  Test (CI)
        - [x]  Review (MR)
        - [x]  Staging (CD)
        - [x]  Production (Total)
    - [x]  Make heuristics more modular
    - [x]  Scope to project
    - [x]  Date range (30 days, 90 days)
    - [x]  Access restriction
- [x]  Test
    - [x]  Find a better way to test these phases
    - [x]  Phases
        - [x]  Issue (Tracker)
        - [x]  Plan (Board)
        - [x]  Code (IDE)
        - [x]  Test (CI)
        - [x]  Review (MR)
        - [x]  Staging (CD)
        - [x]  Production (Total)
    - [x]  Test for "end case happens before start case"
    - [x]  Consolidate helper
- [x]  Miniboss review
- [x]  Performance testing with mock data
- [x]  Improve performance
    - [x]  Pre-calculate "merge requests closing issues
    - [x]  Pre-calculate everything else
- [x]  Test performance against 10k issues
- [x]  Test all pre-calculation code
    - [x]  Ci::Pipeline -> build start/finish
    - [x]  Ci::Pipeline#merge_requests
    - [x]  Issue -> record default metrics after save
    - [x]  MergeRequest -> record default metrics after save
    - [x]  Deployment -> Update "first_deployed_to_production_at" for MR metrics
    - [x]  Git Push -> Update "first commit mention" for issue metrics
    - [x]  Merge request create/update/refresh -> Update "merge requests closing issues"
- [x]  Remove `MergeRequestsClosingIssues` when necessary
- [x]  Changes to unblock Fatih
    - [x]  Add summary data
    - [x]  `stats` should be array
    - [x]  Let `stats` be `null` if all `stats` are null
- [x]  Indexes for "merge requests closing issues"
- [x]  Test summary data
- [x]  Scope everything to project
    - [x]  Find out why tests were passing
- [x]  Filter should include issues/MRs which have made it to production within the range
- [x]  Don't create duplicate `MergeRequestsClosingIssues`
- [x]  Fix tests
- [x]  MySQL median
- [x]  Assign to Douwe for review
- [x]  Fix conflicts
- [x]  Implement suggestions from Yorick's review
    - [x]  Test on PG
    - [x]  Test on MySQL
- [x]  Refactor
    - [x]  Cleanup
        - [x]  What happens if we have no data at all?
        - [x]  Extract common queries to methods / scopes
    - [x]  Remove unused queries
    - [x]  Downtime for foreign key migrations
    - [x]  Find a way around "if issue.metrics.present?" all over the place
    - [x]  Find a way around "if merge_request.metrics.present?" all over the place
    - [x]  Test migrations on a fresh database
        - [x]  MySQL
        - [x]  Pg
- [x]  Access issues
    - While the project is public and the visibility is set to "Everyone with access", you cannot visit the cycle analytics page when signed out.
- [x]  CHANGELOG
- [x]  Implement suggestions from Douwe's review
    - [x]  First set of comments
    - [x]  Second set of comments
    - [x]  Third set of comments
    - [x]  Fourth set of comments
- [x]  Make sure build is green
- [ ]  Make issue for "polish"
- [ ]  EE MR


See merge request !5986

- Pluralize summary titles
- Remove the `run_query` method - always return sql strings from the
  `date_time_sql` methods

1. The spec tests that if:

  - The merge request is merged
  - The target branch is deployed to production
  - The `first_deployed_to_production_at` metric is `nil` (for some reason)
  - The target branch is deployed to production again
  - The `first_deployed_to_production_at` metric stays as `nil` (and is
    not overwritten).

2. Failure only on MySQL due to some datetime weirdness.

- Instead of overriding `create` and `update` in `MergeRequests::BaseService`
- Get all merge request service specs passing

Test if issue authors can access private projects

See merge request !6419

- Don't use `TableReferences` - using `.arel_table` is shorter!
- Move some database-related code to `Gitlab::Database`
- Remove the `MergeRequest#issues_closed` and
  `Issue#closed_by_merge_requests`  associations. They were either
  shadowing or were too similar to existing methods. They are not being
  used anywhere, so it's better to remove them to reduce confusion.
- Use Rails 3-style validations
- Index for `MergeRequest::Metrics#first_deployed_to_production_at`
- Only include `CycleAnalyticsHelpers::TestGeneration` for specs that
  need it.
- Other minor refactorings.

Add docs on Cycle Analytics

Document Cycle Analytics first iteration https://gitlab.com/gitlab-org/gitlab-ce/issues/21170

See merge request !6437

Fixed slash commands not loading

## What does this MR do?

Fixes an issue with slash commands not working when the autocomplete source is loading & then the new issue button is clicked. This also fixes an issue where the autocomplete source is loaded on pages where it isn't actually needed.

## What are the relevant issue numbers?

Closes #21774, #21807

See merge request !6207

[ci skip]

Fix issues with wrong issues/merge request counts when filters are selected

Closes #15356 plus counter for issues and MR are now displayed for the these paths `https://gitlab.com/groups/group-name/issues`  `https://gitlab.com/groups/group-name/merge_requests`  `https://gitlab.com/dashboard/issues` and  `https://gitlab.com/dashboard/merge_requests`

See merge request !4960