Testing Classes with Fixtures

This assumes you have setup your environment as described in [run_tests.md] and that you are in your virtualenv.

If you get stuck, take a peek at the solution.

Refactor the Cattery tests in test_cattery.py to use a py.test fixture.

@pytest.fixture
def cattery_client():
    ...

def test__add_cats__succeeds(cattery_client):
    ...

Try adding a scope argument to pytest.fixture. What happens when you try setting it to scope, session, or module?
```
@pytest.fixture(scope='session')
def cattery_client():
    ...
```
When you are done, run your tests:

(catpy)user@host:~/catinabox$ python setup.py test

When the tests run successfully, push them to your pull request:

(catpy)user@host:~/catinabox$ git commit -a
(catpy)user@host:~/catinabox$ git push origin master