Set up update hook for Packagist

[juho-jaakkola]

The module is now available through packagist (see #11 ).

However, the package has not yet been set to update automatically when a new release tag gets pushed to Github.

Automatic update hook should be set up in Github for the repository. (And also for the other packages: https://packagist.org/packages/divante/ )

See https://packagist.org/about#how-to-update-packages

[afirlejczyk]

I know, I will update changes manually. Everything is up to date in the packagist for this repository.