Add CentOS CR repository and install epel from official packages.

puppet/modules/buildtools/manifests/repos.pp

 class repos {
-	# missing repositories elgis & epel
+	# CR repository
+	package { 'centos-release-cr':
+		ensure		=> 'installed'
+	}
+	# missing repositories elgis, epel, &eox
 	package { 'epel-release':
-		provider	=> 'rpm',
-		ensure		=> 'installed',
-		source		=> 'http://fedora.aau.at/epel/6/i386/epel-release-6-8.noarch.rpm'
+		ensure		=> 'installed'
 	}
 	package { 'elgis-release':
 		provider	=> 'rpm',