* Fix prow set up
* e2e changes
* removing openshift artifacts
* accelerated networking rationalization, with tests
* remove additional sed statements for ip-masq addons
* Update go-dev tools image for go 1.11.2
* remove unused azconst methods
* add support PB6 vm skus
* update azure_const unit test
* update tiller versions in the recent versions of kubernetes
* VSTS VHD pipeline hosted ubuntu pool
* azureconst cruft
* scale: persist scale down in api model
* Add support for Kubernetes 1.11.5
* Fix docker-engine install in VHD pipeline
* remove IsOpenShift from E2E
* replace premature aks-engine reference
* make validate-headers doesn’t exist, revert rename
Jack Francis
Michalis Kargakis