Deploy your own Dub Registry to Heroku via one click

[Seb]

Ever wanted to run your own Dub registry and were too lazy to set 
it up?
It's now one click away.
Simply go to the Dub Registry 
(https://github.com/dlang/dub-registry) and press "Deploy to 
Heroku".
Provided you have a Heroku account, everything else will 
automagically work. Note that Heroku even has a nice free tier 
for hobby projects.

At the moment the Dub registry doesn't expose the Admin interface 
nor supports private packages.
However, it's already very useful for Heroku's GitHub PR preview 
pipeline, e.g.

https://github.com/dlang/dub-registry/pull/278

Also now there's a auto-deployed staging server based on master 
for the Dub registry:

https://dub-registry-staging.herokuapp.com

If you don't like Heroku, you can also use Docker to deploy your 
private Dub registry:

https://github.com/dlang/dub-registry#deploy-your-private-dub-registry-with-docker