Return a PuppetDB version with `puppetdb -v`

This is a cheap way of getting the version of PuppetDB from the current system
without having to make an API call, which is just complex anyway.

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #1110 from kbarber/maint/master/return-version-with-puppetdb-v

Return a PuppetDB version with `puppetdb -v`