Add post-deploy and post-rollback hooks

These replace the custom audit_broadcast_cmd code. An additional env
variable MRSK_RUNTIME is passed to them.

The audit broadcast after booting an accessory has been removed.

lib/mrsk/commands/auditor.rb

@@ -13,14 +13,6 @@ class Mrsk::Commands::Auditor < Mrsk::Commands::Base
       audit_log_file
   end
 
-  # Runs locally
-  def broadcast(line, **details)
-    if broadcast_cmd = config.audit_broadcast_cmd
-      tags = audit_tags(**details, event: line)
-      [ broadcast_cmd,  "'#{tags.except(:recorded_at, :event, :version)} #{line}'", env: tags.env ]
-    end
-  end
-
   def reveal
     [ :tail, "-n", 50, audit_log_file ]
   end