Returns the roster modules

def roster(opts, runner=None, utils=None, whitelist=None):
    '''
    Returns the roster modules
    '''
    return LazyLoader(
        _module_dirs(opts, 'roster'),
        opts,
        tag='roster',
        whitelist=whitelist,
        pack={
            '__runner__': runner,
            '__utils__': utils,
        },
    )