bringing in requirements from test_flaskr
reduced requirements t compile numpy for cache for pandas and matplotlib
added pandas and matplotlib to requirements
added db_create.py
added heroku database URI
changed DATABASE_URI to the default DATABASE_URL created when a database is promoted to default by heroku
added create schema retail to schema.sql
took pybabel out of Procfile
added create schema if not exists to schema.sql
minor corrections to Customer and CustomerWithMarket refs
forgot to add psycopg2