Re-enable Machine Learning on new repository

[lfaucon]

This ticket would benefit greatly from having data in one's local database #42

• Create a new django application "ml" (name could be changed) that contains the Machine Learning code that can be run with the managment command ml_train.
• Ensure the code can runs and produces expected results

[lfaucon]

Hi @OscarVlld

Here is how to work on this task:

1. Clone the repository https://github.com/tournesol-app/tournesol-backend, then cd tournesol-backend
2. Checkout the branch for working on the ml algorithm git checkout ml_train
3. Follow the instructions from the Readme file to run the backend locally
4. Load data in the database uncompress dump.sql.tgz and load the data in your local database psql -d tournesol < scripts/dataset-import/dump.sql
5. Write the algorithm ml_run in file ml/management/commands/ml_train.py and run the algorithm with python manage.py ml_train
6. Add dependencies in ml/ml_requirements.txt
7. Commit and push the changes