Changed 'epel_release' default attribute for 6.X to 6-7
Changed 'epel_release' default attribute for 6.X to 6-7

GannettDigital/chef-yum,autotraderuk/yum,xacaxulu/yum,someara/yum,hippolin/yum-cookbook,streamlinesocial/yum,stan928/yum,mrb/yum,cookbooks/hw-yum,chef-cookbooks/yum,someara/yum,hippolin/yum-cookbook,mattray/yum,ketan/yum,ikkyotech/OpsworksNodeAddons,h4ck3rm1k3/yum,GannettDigital/chef-yum,edmunds-chef/yum,mrb/yum,juliandunn/yum,mattray/yum,stan928/yum,xacaxulu/yum,juliandunn/yum,autotraderuk/yum,mrb/yum,criteo-forks/yum,chef-cookbooks/yum,ketan/yum,GannettDigital/chef-yum,edmunds-chef/yum,hippolin/yum-cookbook,criteo-forks/yum,vkhatri/yum,stan928/yum,h4ck3rm1k3/yum,edmunds-chef/yum,ketan/yum,mattray/yum,cookbooks/oc-yum,autotraderuk/yum,h4ck3rm1k3/yum,xacaxulu/yum,vkhatri/yum,ikkyotech/OpsworksNodeAddons,someara/yum,vkhatri/yum