- added new query parameter trigger and branch to the build resource

By calling /api/:owner/:project/builds?trigger=Travis&branch=notmaster it is
possible to mark how trigger the build and to specify an other than the master branch
as was build. The branch will be neede in the feature to link the tests with it source on github.
Has only be specified if the build was not the master. For an example how to
specify it look at the upload_junitreport.sh script of this project.
- added two nes test to validate the test database entries for e2e testing.

The e2e testing rely on good and complete test data but should not be verify it
. To reduce the confusion why e2e tests are broken verfiy the e2e test data
with an play integration test. So that if an e2e test is broken that was not
caused by unreliable test data. Make the e2e tesing more reliable and more
meaningful.