PYTHON SDK TESTER - A Flask app as SDK client - Can be used to verify PRs

[JFU-GIT]

JIRA Ticket:
BB2-XYZ

This is a minimum sample app for testing python sdk end to end scenario.

User Story or Bug Summary:

What Does This PR Do?

What Should Reviewers Watch For?

If you're reviewing this PR, please check these things, in particular:

The test app (flask based) is packaged as docker compose, with front end (node js react) running on localhost:3000, and app (server) running on localhost:3001.

Steps to start the test app:

1. checkout the PR to local repo
2. edit .bluebutton-config.json at local repo base directory (see example)
3. run command : docker-compose up, or start in native OS mode: python app.py
4. point to localhost:3001 with browser - this will kick off a bene login and authorize flow
5. complete the synthetic bene medicare.gov login and access grant process as prompted by web UI
6. after bene login and access grant, in json format, eob, coverage, patient, profile resources will be shown in browser

example config:

{ "environment": "SANDBOX", "client_id": "<your bb2 app client id here>", "client_secret": "<your bb2 app client secret here>", "callback_url": "http://localhost:3001/api/bluebutton/callback/", "version": 2 }