The `test/integration/integration_config.yml` vars file will now be loaded from the content under test and is now optional.
The `output_dir` and `win_output_dir` vars are now provided by ansible-test.
* Move ansible-test units code into separate dir.
* Fix --explain on "code smell" sanity tests.
* Add --strict-markers to pytest invoctaion.
* Fix classification of units code changes.
* Cache ansible version lookup.
* Fix method of determining ANSIBLE_ROOT.
* Clean up based on PyCharm inspections.
* Generate minimal PKG-INFO without setup.py.
* Use ANSIBLE_LIB_ROOT where possible.
* Use import instead of subprocess to get version.
* Fix install layout type.
* Correct required paths message for installs.
* Update list of files copied during delegation.
* Fix ansible-test entry point.
* Fix pylint issue.
* Fix version lookup on Python 2.x.
* Fix pylint issue.
* Remove unwanted print statement.