New QA scenario to test branches

Steps:

  1. Create a branch for a project
  2. Clone the project
  3. Commit a new file and push the master branch (using QA::Git::Repository)
  4. Create a new file in a new second-branch and push the second-branch branch
  5. Merge second-branch into master and push the master branch
  6. Create a new file in new third-branch and push the third-branch branch
  7. Visit the project's branches page
  8. Assert that the master, second-branch and third-branch are present (optionally assert that their commit is the same as the ones pushed in the previous steps)
  9. Assert that the second-branch branch has a blue merged badge, e.g. Screen_Shot_2018-06-27_at_12.55.28
  10. Delete the third-branch branch
  11. Assert that the third-branch isn't listed anymore
  12. Click the Delete merged branches button
  13. Assert that the second-branch isn't listed anymore