git-state errors out when run from a non-git directory

[Brickster]

$ git state
error: could not lock config file .git/config: No such file or directory
fatal: Not a git repository (or any of the parent directories): .git
Traceback (most recent call last):
  File "/Users/Marcus/Development/bash/git-commands/bin/git-state", line 232, in <module>
    main()
  File "/Users/Marcus/Development/bash/git-commands/bin/git-state", line 229, in main
    state.state(**vars(parser.parse_args()))
  File "/Users/Marcus/Development/bash/git-commands/bin/commands/state.py", line 119, in state
    status = check_output(['git', 'status', '--short', '--untracked-files=all', '--branch']).splitlines()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 573, in check_output
    raise CalledProcessError(retcode, cmd, output=output)
subprocess.CalledProcessError: Command '['git', 'status', '--short', '--untracked-files=all', '--branch']' returned non-zero exit status 128