Bump travis-core
Add SingletonSettingsEndpoint

This class allows to easily add an endpoint for a nested model in
settings.
SshKey is a part of travis-pro-core
Treat repository_id as id for singleton settings
Bump travis-core
Bring back ssh key endpoint, but make it configurable
Return fingerprint along with the public key for repository
Remove Skylight
Update travis-support to sans-newrelic version
Return only simple attributes on PATCH to settings
Bump travis-core
Disable sudo