chore(submodule,test): add 'shebang_unit'

git@github.com:arpinum/shebang_unit.git
refactor(service,permission): wrap test on superuser in function

fixes #52
feat(service,require_superuser): return status

related #52
fix(service) : check directories {/var/run,/var/log,/etc}/mast exists

also known as:
	fix(/var/run/mast): the directory is deleting at reboot

fixes #52
fix(service,start): touch on empty file path

* refactor to leverage inheritance mechanism, let $pidfile flow down children
function ;
* refer to $pidfile instead of $AUTOSSH_PIDFILE ;
* declare $autossh_logfile ;
  * refer to $autossh_logfile instead of $AUTOSSH_LOGFILE ;

fixes #53
docs(service,start): explain 'export ForwardPort' location
style(indent): improve readibility