TESTING: Add guidance on Acceptance test module naming

[notmessenger]

There is an established pattern provided by Ember CLI for the naming of Unit and Component Integration tests modules, implemented in https://github.com/ember-cli/ember-cli/blob/master/blueprints/component-test/index.js and https://github.com/ember-cli/ember-cli-test-info/blob/master/index.js. What these files do not do though is establish/enforce a naming standard for Acceptance test modules. Such guidance should be added to the testing style guide, aligning the format with that already-established pipe-deliminated naming pattern.