test req: Update pytest-mock to 1.1

- From this version onward, pytest-mock is licensed under the MIT
  license.
- Now the plugin also adds introspection information on differing call
  arguments when calling helper methods such as assert_called_once_with.
  The extra introspection information is similar to pytest's and can be
  disabled with the mock_traceback_monkeypatch option.
- mocker.stub() now allows passing in the name for the constructed Mock
  object instead of having to set it using the internal _mock_name
  attribute directly. This is useful for debugging as the name is used
  in the mock's repr string as well as related assertion failure
  messages.
- Monkey patching mock module for friendlier tracebacks is automatically
  disabled with the --tb=native option. The underlying mechanism used to
  suppress traceback entries from mock module does not work with that
  option anyway plus it generates confusing messages on Python 3.5 due
  to exception chaining.
- mock.call is now aliased as mocker.call for convenience.

misc/requirements/requirements-tests.txt

@@ -17,7 +17,7 @@ pytest-catchlog==1.2.2
 pytest-cov==2.2.1
 pytest-faulthandler==1.3.0
 pytest-instafail==0.3.0
-pytest-mock==1.0
+pytest-mock==1.1
 pytest-qt==1.11.0
 pytest-repeat==0.2
 pytest-rerunfailures==2.0.0