Laravel 5.1 auto/self-updatable CMS

We would like to develop a Content Management System from scratch to ship with our future web projects so that our clients can easily maintain their own websites. The CMS will be developed with the Laravel framework.

That said, we were wondering if the following scenario is possible and, if so, whats the best way to realise it:

We would like to create a (master) CMS repo where we will do all the work on, we would only develop on this single repo. A copy/instance (slave) of the CMS should be included/deployed/installed to our client website so each website has it's own CMS.

When changes are required (bug fixes, new features, ...) we develop on the master CMS repo, when everything is well tested the changes need to be deployed to each website with it's own copy of the CMS. Also we would like to bring the logged on user up to date about recents changes made to his CMS with a simple log message or something alike.

So simple said, each website has it's own CMS, but it has to auto/self-update every time the master CMS repo is updated. So every client has the latest release with the newest features.

We considered creating the CMS as a Composer dependency, there are already a few similiar options out there. The main question here is how to - if possible at all - self/auto update the CMS composer package without using command line (composer update) and pull the latest release form the master repo?

Suggestion/ideas are welcome...

Thanks in advance

via Chebli Mohamed