Fix merge conflict

.gitlab-ci.yml

Dockerfile

README.md

barcode_example_generator.py

client/components/barcode_example.png

client/views/ExamEditor.jsx

environment.yml

migrations/versions/b46a2994605b_mult_choice.py

package.json

redis.conf

requirements-dev.txt

requirements.txt

tests/api/test_exams.py

tests/api/test_feedback.py

tests/api/test_mc_option.py

tests/conftest.py

tests/data/.gitignore

tests/data/single-image-a4.pdf

tests/data/two-images-a4.pdf

tests/test_database.py