Fixes to get tests running on RHEL5.

Existing EPEL addition in spec_helper_acceptance wasn't actually working, so pulled in stahnma-epel and applied that in the bindings test, since that's the only place it's actually required.
Merge pull request #515 from mhaskel/rhel5-fixes

Fixes to get tests running on RHEL5.
Add RHEL7 and Ubuntu 14.04.
Merge pull request #516 from apenney/fix-platforms

Add RHEL7 and Ubuntu 14.04.