Replace state=installed with state=present

[Hofer-Julian]

First, let me thank you for your great tutorial, so far it works perfectly.

Do you think you could replace the deprecated form of the apt module state=installed with state=present?
As a beginner it confused me that state=installed was not present in the documentation and only stackoverflow helped.

I can also make a pull request if you'd prefer that.

[turkenh]

Thanks a lot for reporting.
Fixed!