Fix/Update init scripts

[aarontp]

Right now I have PR for some super basic/hacky start-up scripts, but we should update those into something more legit.

[beamcodeup]

Thanks to #134, the init scripts can use the system-level/centralized config file in /etc/turbinia/. This will make this development easier. The init scripts should be based on systemd, which is suppported by major linux distros @ https://en.wikipedia.org/wiki/Systemd#Availability.

[beamcodeup]

Additional note: the update script will not be part of the init scripts as it'd be done through normal packaging.