Bug 982377

postgresql-devel and other packages should be installed in all supported
cases. This led to a Ruby app being unable to build 'pg' gem when
PostgreSQL 8.4 (not 9.2) was embedded.
Revert "No need for Ruby SCL here."

This reverts commit 5432f1671d6edf9cf2b9dd2c0f3f70ad7b282823.

Cucumber test requires "pg" without it being in *.gemspec, so if we
don't guarantee that "pg" gem is available it can cause LoadError.
Merge pull request #3009 from BanzaiMan/dev/hasari/bz982377

Merged by openshift-bot