Fix docker deployment on macOS
I encountered 3 problems when trying to run zesje in docker on macOS Big Sur:
- zesje was crashing when importing opencv because of a missing openGL library so I changed the dependency to the headless version (as advised here)
- zesje was crashing when creating the mysql database because
myinit.sqlwas created in the read-only
/appinstead of the read-write
- Even after fixing the 2 previous issues, I couldn't connect to the server with my browser because I had forgotten to forward the port in Virtualbox so I edited the README to mention it.
I also noticed that after shutting down the container, I can't restart it unless I delete the mysql folder in the docker volume, is that expected?