Build different versions using tags

[Fokko]

Hi Guys,

Right now it always build the master branch. It would be nicer to use tags to build specific versions. So we can use specific version inside of our application and it also makes it easier to test when upgrading to a newer version.

This would require building specific version and tagging them, and also adding them to the Docker Hub: https://hub.docker.com/r/druidio/example-cluster/

Please let me know,

Cheers, Fokko