Github Authentication

[kamoltat]

Current progress:

In teuthology-api you can authenticate with github (you have to be a member of ceph organization) which gives you permission to use teuthology-suite and teuthology-kill.

Todo

• 1. pulpito-ng should have a login/logout button displaying username (or icon) on top right corner.
• 2. Basically login button calls the login logout endpoint in teuthology-api.
• 3. Incorporate some sort of unit-test to this.