Because mpldirdefault = os.path.join(os.getcwd(), '..', '..', '..') in test_pep8_conformance_examples
doesn't resolve to the base directory since os.getcwd() is the base dir in this case.

It works on travis because MPL_REPO_DIR is set. It will also work if the tests are run from the test directory which the above assumes.

This is due to some refactoring of test_coding_standards so it is only broken on the master branch.