use new pycouchdb lib
fix(*) : Status codes (200->204) in Pecan 0.6.0

As of pecan 0.6.0 all responses that are returned with
no content, cannot be set to 200 and are overridden to be
204s.

This patch addresses that change
Merge pull request #33 from TheSriram/pecan_upgrade

fix(*) : Status codes (200->204) in Pecan 0.6.0
fix(config.py):Add cassandra configuration options
Merge pull request #34 from TheSriram/fix_cassandra_config

fix(config.py) : Add cassandra configuration options
Merge remote-tracking branch 'repo/master' into couchdb