R1:1f09e05c683c

Automatically create the Aphlict log directory

Summary: Fixes T6944. Attempt to automatically create the log directory for the Aphlict server. If the directory can't be created, throw a helpful exception.

Test Plan:
# Set `notification.log` to `/var/log/aphlict/aphlict.log`.
# Ran `./bin/aphlict debug` and saw an exception (because the user doesn't have permissions to create the `/var/log/aphlict` directory).
# Ran `sudo chmod 777 /var/log`.
# Ran `./bin/aphlict debug` and saw the `/var/log/aphlict`…