Adds ClientHelpers to Redbooth tests
Add token_url to Redbooth::Client
Adds helpers for the tests:
- Omniauth helper to create auth data for an expired token
- Redbooth helpers refactored. Added helper to stub token request
Allows to pass a Redbooth::Client to new instances of Redbooth::Token
The Redbooth::Token clones the hash of options passed as argument
The auth data generated for the tests will always return an active access_token