(PUP-2918) Remove reduntant acceptance test for new build output

Before this commit, the acceptance tests fail because the output of the
puppet module build action has changed for missing Modulefile and
metadata.json files. With this commit, the acceptance test is removed,
because this behavior is covered in the spec tests.
Merge pull request #2888 from andersonmills/bug/master/pup2918-acceptance_tests_for_build_messages

(PUP-2918) Remove redundant acceptance test for new build output