Dockerhub DOCKER_TAG is empty

[HarelM]

Infra

It seems that when building in dockerhub the DOCKER_TAG is empty for both latest and a specific tag.
The issue is described here:
https://stackoverflow.com/questions/55347752/dockerhub-autobuild-for-a-github-pull-request-using-the-docker-tag-variable
There's a workaround described there, but I would like to avoid using it...
Also this issue:
docker/hub-feedback#508

[HarelM]

There are two options here:

1. Use the dockerhub hook
2. USe appveyor to build and publish docker images.

I'm not sure which I prefer, both are kinda hacks.
Since I can't remove the appveyor site build since I need to run the tests, it's probably better to use it instead of all the hacks in dockerhub.
I.e. disable the dockerhub automatic build and build and publish from appveyor

[HarelM]

This seems to be working as expected in appveyor instead of docker hub, Also latest images will also have their version inside the dlls so opening swagger will show the relevant build.