Cleanup all build artifacts

def clean(docs=False, bytecode=False, extra=''):
    '''Cleanup all build artifacts'''
    patterns = ['build', 'dist', 'cover', 'docs/_build', '**/*.pyc', '*.egg-info', '.tox', '**/__pycache__']
    for pattern in patterns:
        print('Removing {0}'.format(pattern))
        lrun('rm -rf {0}'.format(pattern))