Replace assertEqual(None, *) with assertIsNone in tests

In python-openstackclient some test cases using asserEqual(None, *)
instead of assertIsNone(). assertIsNone method provides clear error message.

Change-Id: I3069a6436d11efa513ae94f21ceab46c498d6e25
Closes-Bug: #1527054

Author: saikiran9392

openstackclient/tests/identity/v3/test_identity_provider.py

@@ -638,5 +638,5 @@ def prepare(self):
 
         # expect take_action() to return (None, None) as
         # neither --enable nor --disable was specified
-        self.assertEqual(None, columns)
-        self.assertEqual(None, data)
+        self.assertIsNone(columns)
+        self.assertIsNone(data)

openstackclient/tests/network/v2/test_network.py

@@ -301,7 +301,7 @@ def test_delete(self):
         result = self.cmd.take_action(parsed_args)
 
         self.network.delete_network.assert_called_with(self._network)
-        self.assertEqual(None, result)
+        self.assertIsNone(result)
 
 
 class TestListNetwork(TestNetwork):
@@ -443,7 +443,7 @@ def test_set_this(self):
         result = self.cmd.take_action(parsed_args)
 
         self.network.update_network.assert_called_with(self._network)
-        self.assertEqual(None, result)
+        self.assertIsNone(result)
 
     def test_set_that(self):
         self._network.is_dirty = True
@@ -463,7 +463,7 @@ def test_set_that(self):
         result = self.cmd.take_action(parsed_args)
 
         self.network.update_network.assert_called_with(self._network)
-        self.assertEqual(None, result)
+        self.assertIsNone(result)
 
     def test_set_nothing(self):
         self._network.is_dirty = False

openstackclient/tests/network/v2/test_router.py

@@ -115,7 +115,7 @@ def test_delete(self):
 
         result = self.cmd.take_action(parsed_args)
         self.network.delete_router.assert_called_with(self._router)
-        self.assertEqual(None, result)
+        self.assertIsNone(result)
 
 
 class TestListRouter(TestRouter):
@@ -235,7 +235,7 @@ def test_set_this(self):
             'name': 'noob',
         }
         self.network.update_router.assert_called_with(self._router, **attrs)
-        self.assertEqual(None, result)
+        self.assertIsNone(result)
 
     def test_set_that(self):
         arglist = [
@@ -257,7 +257,7 @@ def test_set_that(self):
             'distributed': False,
         }
         self.network.update_router.assert_called_with(self._router, **attrs)
-        self.assertEqual(None, result)
+        self.assertIsNone(result)
 
     def test_set_distributed_centralized(self):
         arglist = [