Cleanup of the API.
Updated documentation.
Updated unit tests.
Merge branch master into feature/unit-tests.

Conflicts:
	Service/AbstractService.php
	Service/FileService.php
	Service/PullRequestService.php
	Tests/Service/BranchServiceTest.php
	Tests/Service/CommitServiceTest.php
	Tests/Service/FileServiceTest.php
	Tests/Service/PullRequestServiceTest.php
Fixed unit test.
Merge pull request #7 from MedicoreNL/feature/unit-tests

Feature/unit tests