Create config/secrets.yml with 0600

See merge request !200

Update install and update documentation for 7.13

@JobV Please push directly to this branch and merge if ok.

See merge request !199

Allow to specify flexible list of types in yaml

First part of flexible pipeline build in GitLab CI

Having following `.gitlab-ci.yml`:
```
types:
- test
- deploy
- notify

rspec:
  script: "rspec"

rubocop:
  script: "rubocop"

staging:
  type: deploy
  script: "echo deploy"
  only:
  - master

production:
  type: deploy
  script: "echo production"
  only:
  - tags

dockerhub:
  type: notify
  script: "curl http://docker/hub/web/hook"

downstream:
  type: notify
  script: "curl http://build/downstream/jobs"
```

GitLab CI will trigger two test jobs in parallel, when finished it will trigged either staging or production, when finished it will trigger dockerhub and downstream in parallel.

The UI (screenshots are not for above YAML):
![Screen_Shot_2015-07-10_at_15.56.26](https://gitlab.com/gitlab-org/gitlab-ci/uploads/1f714b73772cf0d44168fb8e20e35561/Screen_Shot_2015-07-10_at_15.56.26.png)
![Screen_Shot_2015-07-10_at_15.57.19](https://gitlab.com/gitlab-org/gitlab-ci/uploads/fc9f458f2ca517d923a4382466fa99eb/Screen_Shot_2015-07-10_at_15.57.19.png)

TODO:
- [x] Implement in CI
- [x] Specs
- [x] Changelog
- [x] CI tests
- [ ] Documentation

/cc @vsizov @sytses @dzaporozhets

See merge request !198

Encrypt variables

/cc @dzaporozhets @jacobvosmaer @vsizov

See merge request !187

Use config/secrets.yml to store session secret and database encryption secret

I took the approach that config/secrets.yml is generated when key is not found.

/cc @vsizov @jacobvosmaer

See merge request !195

```
types:
- test
- deploy
- notify

rspec:
  script: "rspec"

rubocop:
  script: "rubocop"

staging:
  type: deploy
  script: "echo deploy"
  only:
  - master

production:
  type: deploy
  script: "echo production"
  only:
  - tags

dockerhub:
  type: notify
  script: "curl http://docker/hub/web/hook"

downstream:
  type: notify
  script: "curl http://build/downstream/jobs"
```

This will trigger two test jobs in parallel, when finished it will trigged either staging or production, when finished it will trigger dockerhub and downstream in parallel.

Use builds_without_retry to calculate average coverage

/cc @vsizov

See merge request !197

Disable link to runner if it's not assigned to specific project

Fixes 404 when clicking on available runner from project's page

/cc @vsizov

See merge request !196

Disable link to runner if it's not assigned to specific project: fixes 404 when clicking on available runner from project's page

Gem version updates

### Bump rails, jquery-rails, sprockets, sass-rails versions

Addresses security advisories:

- https://groups.google.com/forum/#!topic/ruby-security-ann/XIZPbobuwaY
- https://groups.google.com/forum/#!topic/ruby-security-ann/gcUbICUmKMc

---

### Bump coveralls version

Addresses security issues in its rest-client dependencies:

- https://github.com/rest-client/rest-client/issues/369
- http://www.osvdb.org/show/osvdb/117461

Closes #214

See merge request !194

Addresses security issues in its rest-client dependencies:

- https://github.com/rest-client/rest-client/issues/369
- http://www.osvdb.org/show/osvdb/117461

Addresses security advisories:

- https://groups.google.com/forum/#!topic/ruby-security-ann/XIZPbobuwaY
- https://groups.google.com/forum/#!topic/ruby-security-ann/gcUbICUmKMc

Make configurable builds_path in application.yml

We have a new option in `application.yml`:
```
gitlab_ci:
  builds_path: builds/
```

/cc @marin @vsizov

See merge request !193

Added random salt and hashing to oauth state parameter

This ensures signs state parameter. The generated state is built like this:
```
salt = random_hex(16bytes)
secret = sha256_hex(gitlab_ci_secret + salt + return_to)
state = "salt:secret:return_to"
```

This prevents from faking the state and forcing redirect to provided URL. However this doesn't prevent replay attacks if you know the valid `state` parameter for specific `return_to`. Should we be concerned about it?

/cc @vsizov @jacobvosmaer

See merge request !192

Allow to define per-job allow_failure parameter

It allows to ignore status of specific build when computing status for commit

YAML syntax:
```yaml
rspec:
  script: aa
  allow_failure: true
```

![Screen_Shot_2015-07-08_at_11.28.53](https://gitlab.com/gitlab-org/gitlab-ci/uploads/0af264f026cac18921aef339bcf41fe2/Screen_Shot_2015-07-08_at_11.28.53.png)

/cc @vsizov @sytses

See merge request !191

Build trace in file

https://dev.gitlab.org/gitlab/gitlab-ci/issues/272

See merge request !167