code: def delete_group_policy(self, group_name, policy_name):
          
          params = {'GroupName' : group_name,
                    'PolicyName' : policy_name}
          return self.get_response('DeleteGroupPolicy', params, verb='POST')
docs: Deletes the specified policy document for the specified group.
  
          :type group_name: string
          :param group_name: The name of the group the policy is associated with.
  
          :type policy_name: string
          :param policy_name: The policy document to delete.