This accomplishes the same thing as the previous tests, without using testinfra docker's boilerplate example, which had some drawbacks: Adding @parametrize to the previous version didn't allow overriding the pytest.mark docker arg, image:tag, or cmd with a parametrized test containing different expected results associated with either the alpine/debian tag. Isntead it'd run all the parameters against both tags...e.g. nginx and lighttpd test would run agains both alpine and docker when parametizing on the test level.
