Issue: No PR number is detected on Push events and all builds are
skipped. We want the opposite to be true, so we're running all builds on
merges in hopes of testing better.
An error like
```subprocess.CalledProcessError: Command '['git', 'diff', '--name-only', '95e5cd97d24d9ce809b8287443e9be230a230179...16f5e48fcbc38aca76cbc5ef531491dfd15d0707']' returned non-zero exit status 128.``` exits with code 1 and exits the build and sets the build as successful