Create automated Docker Build

[esteinborn]

In #67 only part of the issue was resolved. in my comment there (included here for quick reference), you'll see there are still a few steps needed in order to set up an automated build for this project.

This only builds the image locally, it does not pull it from the docker hub, which was the original issue here.

The PR that was merged should have set up auto-deployments to docker hub on each successful commit/tag.

In order to successfully set this up, you'll need to follow the documentation on the docker hub, after creating an account there:
https://hub.docker.com/

then follow the instructions to "Create an automated build:"
Link your github account: https://hub.docker.com/account/authorized-services/github-permissions/

after linking, click "Create automated Build" and choose github, and choose TheA11yMachine.

Click create, and you will then be listed on the Docker Hub.

There may be a few more steps to make this happen. But it will stop other people from creating their own, old/outtaded versions of your great application:
https://hub.docker.com/r/nickschuch/the-a11y-machine/
https://hub.docker.com/r/lloydg/the-a11y-machine/
etc

Let me know if you'd like me to help you set this up.