(FM-1951) Ensure Git is installable on EL 5 platforms

Git is not installed on EL 5, but it is not in the repos either.
With this patch, if we are going to install git on an EL 5 platform we
first ensure epel is installed(FM-1951) Ensure Git is installable on
EL 5 platforms
Merge pull request #211 from justinstoller/bug/master/FM-1951-ensure-git

(FM-1951) Ensure Git is installable on EL 5 platforms