Migration Away From `requests` Library

[georgetayqy]

The requests module currently being used requires key and cert files to be stored on the filesystem.

However, since we are migrating the application to the cloud, it might be necessary to store the key and cert files in memory instead to avoid retaining sensitive customer credentials on our cloud systems.

Let's move to migrate away from requests to another modern HTTP request library and SSL library that permits in-memory key files (such as urllib3 and PyOpenSSL).

[georgetayqy]

This issue will be KIV-ed for now, since we need the minimum POC up and running before we can consider how to make the SSL cert and keys more secure.