Create unit tests & documentation for the Python SDK

[mikepsinn]

Create a unit test here:
https://github.com/curedao/curedao-sdk-python/blob/main/test/test_measurement.py

• Go to the CureDAO API Docs
• Select python in the language selector.
• Add the Authentication Bearer access token demo
• Get the Overall Mood variable and check the name matches
• Record a new measurement with a random value between 1 and 100 with the % unit and make sure you get a 201 response
• Get the new measurement and make sure the variable name and value
• Verify that you can get units
• Verify that you can get variable categories