Create 2.0.0-beta2 release

Switching to rc.

Fix has been merged so this is ready for tagging but I'll do one round of testing on dev first in case there's anything else pressing.

Works great... tagging to commence.

https://www.drupal.org/project/quantcdn/releases/2.0.0-rc1 →

https://github.com/quantcdn/drupal/releases/tag/2.0.0-rc1