Add to release notes for 1.8
Add to release notes for 1.8

kubernetes/kops,blakebarnett/kops,kubernetes/kops,aledbf/kops,justinsb/kops,robinpercy/kops,andrewsykim/kops,blakebarnett/kops,chrislovecnm/kops,andrewsykim/kops,andrewsykim/kops,andrewsykim/kops,aledbf/kops,aledbf/kops,pdh/kops,pdh/kops,chrislovecnm/kops,tsupertramp/kops,mad01/kops,tsupertramp/kops,justinsb/kops,tsupertramp/kops,robinpercy/kops,robinpercy/kops,gambol99/kops,blakebarnett/kops,pdh/kops,aledbf/kops,kubernetes/kops,mad01/kops,justinsb/kops,mad01/kops,tsupertramp/kops,blakebarnett/kops,pdh/kops,robinpercy/kops,chrislovecnm/kops,gambol99/kops,gambol99/kops,chrislovecnm/kops,gambol99/kops,mad01/kops