Updating and documenting running demos with plain python

[swcurran]

Current documentation references running a script that doesn't exist and doesn't account for getting the python requirements installed. Trying to run it how we thought would work didn't - things were in folders that are not accessible. Without breaking the docker stuff (or adjusting that as needed), get the "running python" approach working and documented.

Current document: https://github.com/hyperledger/aries-cloudagent-python/blob/master/demo/README.md#running-locally

Installing prerequisites sudo pip3 install -r demo/requirements.txt
Running locally, but not yet working (run from root folder): GENESIS_URL=http://localhost:9000/genesis python -m demo.faber 8020

[swcurran]

Updates made to the scripts and updates made to the documentation.