make centos gitlab-* init scripts more LSB compliant by returning a status return code

I made two fundamental changes: The first is for the init scripts to get the name of the service from the init script file name used to invoke the service. The second is to return a status return code if sidekiq or puma/unicorn is not running. This will enable tools like puppet to properly detect if the service is running or not and it if needs to start the service.