':type policy_arn: string
:param policy_arn: The ARN of the policy to detach
:type role_name: string
:param role_name: Role to detach the policy from'

def detach_role_policy(self, policy_arn, role_name):

    params = {'PolicyArn': policy_arn, 'RoleName': role_name}
    return self.get_response('DetachRolePolicy', params)
