We now support multiple authentication features, because this is how the authentication providers are configured with Concourse now - at deploy time.
All configured authentication methods are applied to the main team by default. This is sort of how it worked anyway in most cases - its just that the default concourse login will work even if Github is configured. This can always be manually overridden, and its not bad to have a failsafe for your admin team.
There are some grab->inject changes to make overrides more intuitive - this was a regression in the last kit version.
This upgrade doesn't require the user to provide any extra params to the env yaml. The only changes that would need to be made would be to manual overrides of auth information.
Notable things:
concourselogin will work even if Github is configured. This can always be manually overridden, and its not bad to have a failsafe for your admin team.