Fix README

1 job for dev-irma in 28 seconds
Status Job ID Name Coverage
  Test
failed #26296
docker
test

00:00:28

 
Name Stage Failure
failed
test Test
    import yaml as pyyaml
E ModuleNotFoundError: No module named 'yaml'
=========================== short test summary info ============================
ERROR test/test_article.py
!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!
=============================== 1 error in 0.16s ===============================
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1