'Get the access_token for the app that can be used for
insights and creating test users
application_id = retrieved from the developer page
application_secret = retrieved from the developer page
returns the application access_token'

@classmethod
def get_app_access_token(cls):

    kwargs = {'grant_type': 'client_credentials', 'client_id': facebook_settings.FACEBOOK_APP_ID, 'client_secret': facebook_settings.FACEBOOK_APP_SECRET}
    response = cls.request('oauth/access_token', **kwargs)
    return response['access_token']
