Expose builds feature
Expose builds feature in project settings (as feature).
Enable it by default for a new projects.
I deliberately named it builds instead of CI, because we actualy allow to run tests using infrastructure built-in GitLab. I'm free to change it.

If we are ok, I'll add feature tests for it.
/cc @sytses @dzaporozhets
See merge request !1767
Refactor complex methods
Make flog part of CI check which is not allowed to fail. I used high score (70) and refactored most complex method. In future releases we should lower acceptable score to something like 40..50
Part of #3444
See merge request !1794
Allow to define cache in `.gitlab-ci.yml`
This extends `.gitlab-ci.yml` syntax to allow specifying caching files and directories between builds, making it easy to preserve ex. gems.
```
cache:
paths:
- .bundle
- vendor/
before_script:
- bundle install --path vendor/
rspec:
script:
- bundle exec rspec
```
This is based on Build Artifacts changes.
/cc@dzaporozhets
See merge request !1786
Implement Build Artifacts
This implements #3028
1. It stores artifacts in shared/artifacts,
1. It adds `artifacts` to `.gitlab-ci.yml`,
1. We use GitLab Workhorse to offload artifacts uploading,
1. To download artifacts it uses GitLab Workhorse X-Sendfile extension,
1. There's one "artifact" per-build. The new upload removes previous one and creates a new one,
1. Default max artifact size is set to 100MB - this can be changed in settings.
Missing things:
1. Support for `.gitlab-ci.yml`: `artifacts: true or git-ls-files` which will upload all non tracked files,
1. Artifacts passing between builds.
GitLab Workhorse changes: https://gitlab.com/gitlab-org/gitlab-workhorse/merge_requests/5
GitLab Runner changes: https://gitlab.com/gitlab-org/gitlab-ci-multi-runner/merge_requests/46
Syntax:
```
artifacts:
untracked: true # default: false
paths: # default: empty
- bin/files
```
See merge request !1584
- Offloads uploading to GitLab Workhorse
- Use /authorize request for fast uploading
- Added backup recipes for artifacts
- Support download acceleration using X-Sendfile
* fix commit duration graph
* make graphs responsive
* fix wrong padding
* add a bit of explanation to colors
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Sherlock will be a new GitLab specific tool for measuring the
performance of Rails requests (and SideKiq jobs at some point). Some of
the things that are currently tracked:
* SQL queries along with their timings, backtraces and query plans
(using "EXPLAIN ANALYZE" for PostgreSQL and regular "EXPLAIN" for
MySQL)
* Timings of application files (including views) on a per line basis
* Some meta data such as the request method, path, total duration, etc
More tracking (e.g. Rugged or gitlab-shell timings) might be added in
the future.
Sherlock will replace any existing tools we have used so far (e.g.
active_record_query_trace and rack-mini-profiler), hence the
corresponding Gems have been removed from the Gemfile.
Sherlock can be enabled by starting Rails as following:
ENABLE_SHERLOCK=1 bundle exec rails s
Recorded transactions can be found at `/sherlock/transactions`.