Parametrise the recipe fixture in tests

[Rocco Meli]

The recipe fixture could be parametrised, instead of returning a list of recipes to loop over in other test functions.

stackinator/unittests/test_schema.py

Lines 26 to 28 in dbd21f1

 @pytest.fixture 
 def recipe_paths(test_path, recipes): 
     return [test_path / "recipes" / r for r in recipes]