Hackebrot convert test cookiecutter local no input

Convert `test_main.TestCookiecutterLocalNoInput` to `py.test` syntax this time using a parametrized fixture for two of the tests (slash/no-slash).
The original tests of `TestCookiecutterLocalNoInput` named `test_cookiecutter` and `test_cookiecutter_no_slash` have been identical except for the `/` in the `input_dir`.

The fixture labelled `bake` is getting called once for each of the specified params resulting in `test_cookiecutter` being run twice. Hope this helps!