Enable puppet coverage reports

[bastelfreak]

Those are required to ensure a certain level of coverage and it's the
current community best practice to have those reports enables. pdk
should reflect that.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}