fix puppetlabs-inifile version

There is no 0.5.0 version of the puppetlabs-inifile module. http://forge.puppetlabs.com/puppetlabs/inifile

This is mostly not an issue since most module tools resolve it correctly but I had an issue with ```puppet module install puppetlabs-inifile --version 0.5.0``` in the rspec-system tests.