Do not allow a negative Build interval
Do not allow a negative timeout
Merge pull request #310 from jojosch/polling-non-negative

Do not allow a negative Build interval and timeout
Explain the features better.
Merge branch 'explain-featured' of /home/git/repositories/gitlab/gitlab-ci
Merge branch 'master' of github.com:gitlabhq/gitlab-ci
Reset runner id for Build.create_from

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Use rake task with whenever instead of runner

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Update docs

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>