This adds GitHub support. Added the test I used to verify that the GitHub payload has the same structure as the one from GitLab
Merge branch 'master' into feature/GitHub-support

Conflicts:
	lib/application.rb
This adds a GitService class that GitLab and GitHub inherits from. The GitHub class supports public repos only.
Merge pull request #7 from GeirT/feature/GitHub-support

Feature/github support