(maint) Reconcile changes from FOSS RHEL7 mockstub with PE RHEL7 mockstub

This will ensure we're using a consistently usable base when we try to
build RHEL7 PE packages.
(maint) Remove errant conditionals from RHEL7 PE mockstub
Merge pull request #62 from mckern/use_epel

(maint) Reconcile changes from FOSS RHEL7 mockstub with PE RHEL7 mockstubs