Audit details (#1)

Audit details

* Audit logs and broadcasts accept `details` whose values are included as log tags and MRSK_* env vars passed to the broadcast command
* Commands may return execution options to the CLI in their args list
* Introduce `mrsk broadcast` helper for sending audit broadcasts
* Report UTC time, not local time, in audit logs. Standardize on ISO 8601 format

lib/mrsk/cli/base.rb

@@ -73,9 +73,7 @@ module Mrsk::Cli
       end
 
       def audit_broadcast(line)
-        if broadcast = MRSK.auditor.broadcast(line)
-          system(MRSK.auditor.broadcast_environment(line), broadcast)
-        end
+        run_locally { execute *MRSK.auditor.broadcast(line), verbosity: :debug }
       end
 
       def with_lock