Setting up Google Play Universal Receipt Store Auth

In order for our apps to provide and validate Google Play purchases, we utilise the Android Publisher API to query and check end-users' subscriptions and provide them appropriate access to content. Setting this up requires creation of a 'Service Account' which provides access credentials to Google services in order for our servers to access data on your Google Developer account.

See http://docs.pugpig.com/en_US/google-play-store/google-service-account-key.