':type policy_arn: string
:param policy_arn: The ARN of the policy to detach
:type user_name: string
:param user_name: User to detach the policy from'

def detach_user_policy(self, policy_arn, user_name):

    params = {'PolicyArn': policy_arn, 'UserName': user_name}
    return self.get_response('DetachUserPolicy', params)
