Let dockerhub point to new location

[drwetter]

While this repo has been moved to https://github.com/testssl/testssl.sh now dockerhub is not following the link from the old to the new location as browsers do. Which as a result means it is currently serving the existing images only.

For organizations I currently see here only the old location (drwetter) and another one. https://github.com/testssl/ doesn't show up (yet?). There doesn't seem to be a possibility to add organizations here.

If anybody can help that would be appreciated.