Using a branch-per-feature git flow, you might have a trouble with quality assurance and testing, if your project is closely connected with OAuth 2 providers like Google, Facebook etc. In such a case you need to update the list of callbacks manually to let your QAs to login into the separate branches and test the features.
We created OAuth2.me service to set the callback url only once.
gem 'oauth2-me', github: 'jetthoughts/oauth2-me-ruby'
$ bundle