Create requirements folder for Dependabot

[danielvschoor]

This issue requires some discussion. Dependabot automatically looks for either a requirements.txt file (which we have in /pip/), or all txt files in a requirements folder to determine which dependencies needs updates. We currently have 4 requirements files, namely: requirements.DEV.txt requirements.STAGING.txt requirements.PROD.txt

If we want to check all these files, we'll need to create a requirements folder, and move these files in there. We'll need to update the pip-install.py file to look at the new folder.

The problem is that when Dependabot creates a PR, Github Actions automatically runs, but it only uses requirements.txt and not any of the other requirement files, so any PRs that update those won't get tested.

There are 3 options, I think:

1. Create the requirements folder, move the files, and run Dependabot on all these files. We'll have to test locally to ensure that nothing breaks.
2. Same as 1, but run tests on every requirements.txt file on Github Actions (potentially slow and redundant)
3. Ignore the other files, and update them manually whenever we remember.

Thoughts?