Rainforest QA supports using your Github credentials to login. This article will cover how to create an account using Github and how to link your existing Rainforest account to your Github profile.
If you already have a Rainforest account, you can link it to your Github account by going to "My Account" in your account settings. You can then click the "Connect with your Github account" button.
Once you click this, you'll be asked by Github to grant permission to Rainforest to access your public profile. Accept and you should be redirected back to Rainforest.
After you've done this, you will now be able to login into Rainforest using the "Login with Github" button on the login page.