Rename CDN to Poppy

Renamed modules from "CDN" to "Poppy"
Updated tests (Tox), Pep8, conf files
Updated keyspace name in Cassandra
Updated Docker files
Added basic index Sphinx Doc.


When referring to the product i tried to use "Poppy".  When referring to code or application I have used "poppy".  I think above it should be "P".  i will adjust. Thanks.