Untested python -m marbles --version behavior

[thejunglejane]

__main__.py#L42-L51

if len(sys.argv) > 1 and sys.argv[1] == '--version':  # condition on this line is never true
    import marbles.core 
    print('marbles.core version: {}'.format(marbles.core.__version__)) 
    try: 
        import marbles.mixins 
    except ImportError: 
        print('marbles.mixins not installed') 
    else: 
        print('marbles.mixins version: {}'.format(marbles.mixins.__version__)) 
    sys.exit(0)