Set up tests so that they can be run separately (integration tests)

The goal is that the layout unit test would also run in a cross browser testing platform (Browserstack, Saucelabs, Crossbrowsertesting, Testingbot), separately from the Wallaby interactive test runner.

- add environment variables to toggle parts of the test related to Wallaby/Mocha
- name the test files that should be run on the testing service (not business logic unit tests)