Adds missing aliases for NonCallableMock and create_autospec

[mlhamel]

This PR is adding support for the following missing aliases:

• NonCallableMock :: (https://docs.python.org/3/library/unittest.mock.html#unittest.mock.NonCallableMock)
• create_autospec :: https://docs.python.org/3/library/unittest.mock.html#create-autospec

It simply adds the missing instantiation into MockFixture and adds it also into the corresponding test.

[coveralls]

Coverage remained the same at ?% when pulling 1ff24c9 on mlhamel:adds-support-for-noncallable-mock into 680d4ee on pytest-dev:master.

[coveralls]

Coverage remained the same at ?% when pulling 27ae485 on mlhamel:adds-support-for-noncallable-mock into 680d4ee on pytest-dev:master.

[nicoddemus]

Thanks a lot @mlhamel!

[nicoddemus]

1.8.0 is out, thanks again!