message: Updated vcx pytho demo readme
diff: -This directory contains 3 files:
  +# Running the Alice/Faber Pytho demo
  +
  +There are 2 versions of this demo, the original version (faber.py and alice.py), and a slightly modified version (faber-pg.py and alice-pg.py) that supports postgres wallet storage, and illustrated how the vcx object serializtion/deserialization can be used.
  +
  +## Original Demo
  +
  +This demo consists of 3 files:
  faber.py - a script that acts as an institution/enterprise by sending a connection request, writing a schema/cred_def to the ledger, sending a credential offer, and requesting proof.
  @@ -17,3 +23,21 @@ To run these follow the next steps:
  6) Once the connection is established the faber.py script will send a credential offer, credential and proof request automatically.
  The alice.py script will request a credential, store it and offer proof when asked.
  Once they have interacted they will both exit.
  +
  +## Slightly Modified Demo
  +
  +This demo is run using the following files:
  +
  +faber-pg.py - same as faber.py, however once a connection is established, this script provides a menu:
  + 1 = send credential to Alice
  + 2 = send proof request to Alice
  + 3 = poll the Alice connection to see if Alice has sent any messages
  + x = stop and exit
  +
  +alice-pg.py - same as alice.py, however once a connection is established, this script provides a menu:
  + y = poll the connection for messages (credential offers or proof requests)
  + n = stop and exit
  +
  +To create the alice/faber wallets using postgres storage, just add the "--postgres" option when running the script.
  +
  +Internally, the scripts serialize and deserialize the vcx objects between operations. In "real life", these serialized objects could be stored to the database or to wallet non-secrets storage.
  