Flunentd to GCP logging node level configuration

This is the setup to conditionally support logging using Fluentd and GCP. If enabled with FLUENTD_GCP=true then this will install a manifest on each node which will instantiate a Fluentd instance (in a Docker container) on each node which causes logging data to be ingested into Google Compute Platform. When this option is enabled the minion are created with extra scopes to allow the required logging API calls to be authenticated.