Traceback when .gitlab-ci.yml is missing

If you run gle on a directory without a .gitlab-ci.yml (eg your home directory) instead of seeing a nice error message you see a large traceback:

Traceback (most recent call last):
  File "/Users/username/Library/Python/3.9/bin/gle", line 8, in <module>
    sys.exit(run())
  File "/Users/username/Library/Python/3.9/lib/python/site-packages/gitlabemu/runner.py", line 74, in run
    loader.load(fullpath)
  File "/Users/username/Library/Python/3.9/lib/python/site-packages/gitlabemu/configloader.py", line 505, in load
    self.config = self._read(filename)
  File "/Users/username/Library/Python/3.9/lib/python/site-packages/gitlabemu/configloader.py", line 484, in _read
    objdata = read(filename, **kwargs,
  File "/Users/username/Library/Python/3.9/lib/python/site-packages/gitlabemu/configloader.py", line 332, in read
    with open(yamlfile, "r") as yamlobj:
FileNotFoundError: [Errno 2] No such file or directory: '/Users/username/.gitlab-ci.yml'