Execute commands in runner via WebSocket

This enables executing commands in runners and forwarding input and
output between the runner and the websocket to the client.

Co-authored-by: Maximilian Paß <maximilian.pass@student.hpi.uni-potsdam.de>

nomad/job.go

@@ -7,6 +7,7 @@ import (
 
 const (
 	TaskGroupNameFormat = "%s-group"
+	TaskName            = "default-task"
 )
 
 // LoadJobList loads the list of jobs from the Nomad api.