Upgrading Python and packages using Poetry

[Didayolo]

As discussed in #1023 and #1410, we should regularly upgrade Python version and other packages.

Apparently Poetry is an interesting tool to help with resolving package conflicts.

We need to keep in mind that we have several Dockerfiles et requirements.txt files in this project. Putting this in place may be tricky at first but very useful in the future.

Requirements files

• https://github.com/codalab/codabench/blob/develop/requirements.txt
• https://github.com/codalab/codabench/blob/develop/requirements.dev.txt
• https://github.com/codalab/codabench/blob/develop/compute_worker/compute_worker_requirements.txt

Dockerfiles

• https://github.com/codalab/codabench/blob/develop/Dockerfile
• https://github.com/codalab/codabench/blob/develop/Dockerfile.builder
• https://github.com/codalab/codabench/blob/develop/Dockerfile.celery
• https://github.com/codalab/codabench/blob/develop/Dockerfile.compute_worker
• https://github.com/codalab/codabench/blob/develop/Dockerfile.compute_worker_gpu
• https://github.com/codalab/codabench/blob/develop/Dockerfile.flower
• https://github.com/codalab/codabench/blob/develop/Dockerfile.rabbitmq

Related branch: https://github.com/codalab/codabench/tree/issue_1413

[Didayolo]

Solved by #1416