[DAEMON-196] appcd-core: Ensure the pid file always exists
|Appc Daemon 1.0.0
When the daemon is running, it creates a pid file in the appcd home dir. This is critical as it is used to determine if the daemon is running. If this file is deleted while the daemon is running, this can be problematic as the zombie daemon process will need to manually terminated by the user.
- Chris Barber 2017-11-28