Merge branch 'artifacts' into 'master'

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

2 files changed, 2 insertions, 0 deletions

diff --git a/config/initializers/1_settings.rb b/config/initializers/1_settings.rb
index 8192d727f2a..302124bd977 100644
--- a/config/initializers/1_settings.rb
+++ b/config/initializers/1_settings.rb
@@ -186,6 +186,7 @@ Settings.gitlab_ci['all_broken_builds']     = true if Settings.gitlab_ci['all_br
 Settings.gitlab_ci['add_pusher']            = false if Settings.gitlab_ci['add_pusher'].nil?
 Settings.gitlab_ci['url']                   ||= Settings.send(:build_gitlab_ci_url)
 Settings.gitlab_ci['builds_path']           = File.expand_path(Settings.gitlab_ci['builds_path'] || "builds/", Rails.root)
+Settings.gitlab_ci['max_artifacts_size']    ||= 100 # in megabytes
 
 #
 # Reply by email
diff --git a/config/routes.rb b/config/routes.rb
index 2028ea938e4..c892c034f01 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -611,6 +611,7 @@ Gitlab::Application.routes.draw do
           member do
             get :status
             post :cancel
+            get :download
             post :retry
           end
         end