Use unittest.mock instead of third party mock

Now that we no longer support py27, we can use the standard library
unittest.mock module instead of the third party mock lib.

Change-Id: I24daffca6667325bd7710e02e0b6a057935e9ac9
Signed-off-by: Sean McGinnis <sean.mcginnis@gmail.com>

muranoagent/tests/unit/executors/test_chef.py

@@ -12,9 +12,10 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from unittest import mock
+
 import fixtures
 import json
-import mock
 from mock import ANY
 import os
 

muranoagent/tests/unit/executors/test_puppet.py

@@ -12,8 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from unittest import mock
+
 import fixtures
-import mock
 
 from muranoagent import bunch
 from muranoagent import exceptions as ex

muranoagent/tests/unit/test_app.py

@@ -12,8 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from unittest import mock
+
 import fixtures
-import mock
 import ssl as ssl_module
 
 from muranoagent import app

muranoagent/tests/unit/test_files_manager.py

@@ -12,8 +12,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
 import os.path
+from unittest import mock
 
 from muranoagent import bunch
 from muranoagent.common import config as cfg

muranoagent/tests/unit/test_script_runner.py

@@ -13,7 +13,7 @@
 #    under the License.
 
 import git
-import mock
+from unittest import mock
 
 from muranoagent import bunch
 from muranoagent.common import config as cfg

test-requirements.txt

@@ -4,7 +4,6 @@
 hacking>=3.0,<3.1.0 # Apache-2.0
 unittest2>=1.1.0 # BSD
 coverage>=4.5.1 # Apache-2.0
-mock>=2.0.0 # BSD
 testtools>=2.3.0 # MIT
 stestr>=2.0.0 # Apache-2.0
 oslotest>=3.3.0 # Apache-2.0