Added the sym-link to the GitLab service executable in the /etc/init.d/.

[valdemon]

The proposed fix gets a rid of the following error, while provisioning on the Debian-7 VM:

==> gitlab: Notice: /Stage[main]/Gitlab::Config/Exec[gitlab_reconfigure]/returns: gitlab Reconfigured!
==> gitlab: Notice: /Stage[main]/Gitlab::Config/Exec[gitlab_reconfigure]: Triggered 'refresh' from 1 events
==> gitlab: Error: Execution of '/usr/sbin/update-rc.d gitlab defaults' returned 1: update-rc.d: error: unable to read /etc/init.d/gitlab
==> gitlab: update-rc.d: using dependency based boot sequencing
==> gitlab: Error: /Stage[main]/Gitlab::Service/Service[gitlab]/enable: change from false to true failed: Execution of '/usr/sbin/update-rc.d gitlab defaults' returned 1: update-rc.d: error: unable to read /etc/init.d/gitlab
==> gitlab: update-rc.d: using dependency based boot sequencing