Auto detect new dependencies and update requirements.txt

[rathorevaibhav]

Describe the task
Adding new dependencies is a manual step right now. The developer needs to run the following command in order to stay up to date:

pip freeze > requirements.txt

Expected behavior
We need an automated way that automatically captures when a new package is installed (maybe when we run pip install) and adds it to requirements.txt. Something like npm does when we use npm install, it adds to package.json and package-lock.json