Interim commit.
Migrated user model.
Create subscriptions.
Merge branch 'master' into account-types
Interim commit - have a GoCardless app
Integrated account upgrade with GC confirmation.
Interim commit.
Test runner refactor.
Update subscription upgrade template.
Merging account types.
Allows a user to upgrade their account by creating a £20/m subscription via GoCardless.
closes #56