'Updates a security group.
For a full list of available parameters, please refer to the official
API reference:
http://developer.openstack.org/api-ref/networking/v2/index.html#update-security-group'

def update_security_group(self, security_group_id, **kwargs):

    uri = ('/security-groups/%s' % security_group_id)
    post_data = {'security_group': kwargs}
    return self.update_resource(uri, post_data)
