When you log in to concourse, either using basic auth or github based authentication, the interface:

• doesn't indicate that you are logged in (it could print the user name - this is useful when you're working with multiple instances of concourse which have same pipelines, e.g. dev/test/staging/production and you have different logins to each)
• there is no log out button. I tried really hard to find it but no success. There is /login URL path, but no /logout