Imports config based on environment.
    :return:

def get_config():
    """
    Imports config based on environment.
    :return:
    """
    app_module = os.getenv('APP_MODULE')
    if not app_module:
        err = 'Unable to bootstrap application APP_MODULE is not defined'
        raise x.BootstrapException(err)

    app_config = os.getenv('APP_CONFIG')
    if not app_module:
        err = 'Unable to bootstrap application APP_CONFIG is not defined'
        raise x.BootstrapException(err)

    try:
        config_class = import_string(app_config)
    except ImportError:
        err = 'Failed imported config file [{}]'
        raise x.BootstrapException(err.format(app_config))

    # and return
    config = config_class()
    return config