This method can be used for upgrades and upgrades too but it hasn't been tested thoroughly as I need to test against subscriptions purchased with Stripe payment gateway.
Changes include in this commit:
- Move common methods from limitmonitor/task_resources/subscription.py to limitmonitor/common.py
- Add disable() and is_enabled() methods for Limit class.
- Rise exception when we cannot terminate a Tunnel account.
- Add get_enabled_limits() method for User class.
- Remove redundant code in process_pending_registrations_user.
- Use limit.is_enabled() instead of limit.is_active.