Various bigip_pool fixes (#32161)

* corrects copyrights and mocks in unit tests
* fixes module code to include code to cleanup tokens

test/units/modules/network/f5/test_bigip_pool.py

@@ -1,21 +1,7 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright 2017 F5 Networks Inc.
-#
-# This file is part of Ansible
-#
-# Ansible is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# Ansible is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public Liccense for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+# Copyright (c) 2017 F5 Networks Inc.
+# GNU General Public License v3.0 (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
 
 from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
@@ -171,8 +157,8 @@ class TestManager(unittest.TestCase):
         )
 
         mm = ModuleManager(client)
-        mm.create_on_device = lambda: True
-        mm.exists = lambda: False
+        mm.create_on_device = Mock(return_value=True)
+        mm.exists = Mock(return_value=False)
 
         results = mm.exec_module()