Introduce versioning about openstreetmap-tile-server

[Overv]

I've partitioned the current history into a couple of different milestones and pushed versioned tags/images for them.

[Istador]

Nice anecdote from this week regarding this issue.

On our productive server, a colleague of mine pulled the newest image version and throw away the old one that we were using. He wondered why it wasn't starting anymore, and figured based on error messages, that it was because of postgres 10/12. So he changed a few lines by me that were still referring to 10. The service seemed to run then and served tiles, except, unknown to him, that the rendering wasn't working anymore. A day later the amount of errors due to the client render requests overloaded the docker service.

I was able to pull the 1.0 tag from the docker hub, but because it was builded over a year after the time when 5906892 was around as latest, almost all of the software packages inside of the image had altered. Due to changes to openstreetmap-carto in that time, we can't use our custom mapnik.xml anymore with the 1.0 image and have to adjust/redo all of our customizations with a newer version.

That's not your fault, but mine. I should have pushed the image that we were using to our own private docker repository for safekeeping. Remember: never use latest.