OAuth2 `client_id` vs `clientId`

[tomkersten]

The recent refactor for tests resulted in the expected Client ID config param changing from client_id to clientId. Not a big deal once found, however it was undocumented so took a bit to track down. I'm not sure if we want it to be clientId or to restore it to client_id, as all other config params are underscore-based (redirect_uri, etc).

Thoughts?

[camfou]

Hi, this PR fix this issue : #374