Update stable channel for kops 1.5.0, k8s 1.4.8
Update stable channel for kops 1.5.0, k8s 1.4.8

This should not impact kops 1.4 users:

* The first image is the 1.4 image
* The cluster.kubernetesVersion is 1.4.8
* kops 1.4 will not read kubernetesVersion nor kopsVersion

We do bump the recommended k8s to 1.4.8

leandrocr/kops,tsupertramp/kops,zytek/kops,sp-borja-juncosa/kops,MadDogTechnology/kops,sethpollack/kops,justinsb/kops,tsupertramp/kops,sethpollack/kops,blakebarnett/kops,luomiao/kops,robinpercy/kops,andrewsykim/kops,dacohen/kops,justinsb/kops,ikropotov/kops,andrewsykim/kops,luomiao/kops,pdh/kops,austinmoore-/kops,DualSpark/kops,andrewsykim/kops,leandrocr/kops,WillemMali/kops,robinpercy/kops,WillemMali/kops,mad01/kops,WillemMali/kops,BradErz/kops,BradErz/kops,andrewsykim/kops,aledbf/kops,pdh/kops,tsupertramp/kops,gambol99/kops,chrislovecnm/kops,DualSpark/kops,luomiao/kops,kris-nova/kops,luomiao/kops,DualSpark/kops,gambol99/kops,sethpollack/kops,austinmoore-/kops,sethpollack/kops,mad01/kops,reactiveops/kops,leandrocr/kops,faraazkhan/kops,mad01/kops,aledbf/kops,faraazkhan/kops,ikropotov/kops,blakebarnett/kops,aledbf/kops,dacohen/kops,chrislovecnm/kops,kubernetes/kops,gambol99/kops,ikropotov/kops,reactiveops/kops,reactiveops/kops,WillemMali/kops,blakebarnett/kops,dacohen/kops,sp-borja-juncosa/kops,justinsb/kops,austinmoore-/kops,chrislovecnm/kops,BradErz/kops,austinmoore-/kops,chrislovecnm/kops,kris-nova/kops,kubernetes/kops,kris-nova/kops,BradErz/kops,MadDogTechnology/kops,MadDogTechnology/kops,pdh/kops,zytek/kops,robinpercy/kops,reactiveops/kops,aledbf/kops,tsupertramp/kops,kubernetes/kops,MadDogTechnology/kops,sp-borja-juncosa/kops,zytek/kops,zytek/kops,faraazkhan/kops,DualSpark/kops,pdh/kops,ikropotov/kops,robinpercy/kops,dacohen/kops,leandrocr/kops,sp-borja-juncosa/kops,kris-nova/kops,mad01/kops,gambol99/kops,faraazkhan/kops,blakebarnett/kops