Ark
refs https://github.com/TryGhost/Team/issues/1083 The Offers service is going to need access to the StripeAPIService too, so we need to move it out of the @tryghost/members-api module and make it accessible to both.
refs: https://github.com/TryGhost/Team/issues/856 refs: https://github.com/TryGhost/Team/issues/756 - The .test.js extension is better than _spec.js as it's more obvious that it's an extension - It also meaans we can use the --extension parameter in mocha, which should result in a better default behaviour for `yarn test` - It also highlights that some of our tests were named incorrectly and were not (and still will not be) run (see https://github.com/TryGhost/Team/issues/856) - Note: even with this change, `yarn test` is throwing errors, I believe because of this issue https://github.com/TryGhost/Team/issues/756