Ko does not work on azurecr

[n3wscott]

I am trying to use ko with azurecr.io. My registry is n3wscott.azurecr.io.

Say, I have an image: n3wscott.azurecr.io/foo:latest

I can docker push to this fine.

I try to build and push with ko and I get a 401 error on the push step.

It looks like if I add a path to my cr uri it works: KO_DOCKER_REPO=n3wscott.azurecr.io/x ko ...

Now ko works correctly and pushes to n3wscott.azurecr.io/x/foo:latest which is not exactly what I want and not how the azurecr docs tell you to setup the docker repo.

Likely an issue with this PR: #117

cc: @jonjohnsonjr