Parse command line flags added to `rest_api` command.

def parse_args(args):
    """Parse command line flags added to `rest_api` command.
    """
    parser = argparse.ArgumentParser(
        description='Starts the REST API application and connects to a '
        'specified validator.')

    parser.add_argument('-B', '--bind',
                        help='identify host and port for API to run on \
                        default: http://localhost:8008)',
                        action='append')
    parser.add_argument('-C', '--connect',
                        help='specify URL to connect to a running validator')
    parser.add_argument('-t', '--timeout',
                        help='set time (in seconds) to wait for validator \
                        response')
    parser.add_argument('--client-max-size',
                        type=int,
                        help='the max size (in bytes) of a request body')
    parser.add_argument('-v', '--verbose',
                        action='count',
                        default=0,
                        help='enable more verbose output to stderr')
    parser.add_argument('--opentsdb-url',
                        help='specify host and port for Open TSDB database \
                        used for metrics')
    parser.add_argument('--opentsdb-db',
                        help='specify name of database for storing metrics')

    try:
        version = pkg_resources.get_distribution(DISTRIBUTION_NAME).version
    except pkg_resources.DistributionNotFound:
        version = 'UNKNOWN'

    parser.add_argument(
        '-V', '--version',
        action='version',
        version=(DISTRIBUTION_NAME + ' (Hyperledger Sawtooth) version {}')
        .format(version),
        help='display version information')

    return parser.parse_args(args)