Adds tests to make sure all the `nginx.conf` directives (the redirects and rewrites and such) are all correct.
- Uses the `busted` framework
- The tests are run in a Docker container by the bash script `test.sh`
- Self-signed certs are generated in `Dockerfile` for all the domain names
- Adds new `Makefile` commands: `test`, `image-build` and `image-rm`
Reviewed-on: #1
Co-authored-by: Catalin Mititiuc <webdevcat@proton.me>
Co-committed-by: Catalin Mititiuc <webdevcat@proton.me>
