Upgrade puppetlabs-postgresql to fix concat module

* install_modules.sh: Upgrade puppetlabs-postgresql to version 3.0.0 to
fix conflicts in the concat module. Old postgresql uses ripienaar's
module other modules want puppetlabs' concat module. This upgrade resolves
that conflict.

Change-Id: I3813abea48d933421ebb4f81e84e783fa51618db
Merge "Upgrade puppetlabs-postgresql to fix concat module"