Prototype Python script that uses Twitter Stream API

[jpowerwa]

Get example script in place that uses Twitter Stream API. Intent is threefold:

1. Provide a jumping off point for a real tool that listens for tweets from particular users.
2. Demonstrate chosen Python wrapper library.
3. Demonstrate best Python 3 coding practices for presterity/twitter-integration, to the degree that such practices are known.

Deliverable: Python script reviewed and merged to master.