v0.15.39

Changes

webhook: refactor test (#2251)
This is a preparation for removing kubernetes dependency

Docker image

Docker image is available in Zalando's Open Source registry:

docker run -it registry.opensource.zalan.do/teapot/skipper:v0.15.39 skipper --help
# arm64
docker run -it registry.opensource.zalan.do/teapot/skipper-arm64:v0.15.39 skipper --help
# arm v7 32bit
docker run -it registry.opensource.zalan.do/teapot/skipper-armv7:v0.15.39 skipper --help