List all available locations

def avail_locations(call=None):
    '''
    List all available locations
    '''
    if call == 'action':
        raise SaltCloudSystemExit(
            'The avail_locations function must be called with '
            '-f or --function, or with the --list-locations option'
        )

    ret = {}
    for key in JOYENT_LOCATIONS:
        ret[key] = {
            'name': key,
            'region': JOYENT_LOCATIONS[key]
        }

    # this can be enabled when the bug in the joyent get data centers call is
    # corrected, currently only the European dc (new api) returns the correct
    # values
    # ret = {}
    # rcode, datacenters = query(
    #     command='my/datacenters', location=DEFAULT_LOCATION, method='GET'
    # )
    # if rcode in VALID_RESPONSE_CODES and isinstance(datacenters, dict):
    #     for key in datacenters:
    #     ret[key] = {
    #         'name': key,
    #         'url': datacenters[key]
    #     }
    return ret