Add null logging handler to cassandra package
Add null logging handler to cassandra package

This prevents spurious warnings like 'No handlers could be found for
logger "cassandra.cluster"'.  This will not affect normal logging.

kishkaru/python-driver,datastax/python-driver,mambocab/python-driver,coldeasy/python-driver,sontek/python-driver,mike-tr-adamson/python-driver,jfelectron/python-driver,kracekumar/python-driver,mobify/python-driver,HackerEarth/cassandra-python-driver,beobal/python-driver,bbirand/python-driver,bbirand/python-driver,sontek/python-driver,thobbs/python-driver,jregovic/python-driver,thobbs/python-driver,jregovic/python-driver,datastax/python-driver,vipjml/python-driver,tempbottle/python-driver,markflorisson/python-driver,vipjml/python-driver,yi719/python-driver,yi719/python-driver,kishkaru/python-driver,beobal/python-driver,HackerEarth/cassandra-python-driver,tempbottle/python-driver,thelastpickle/python-driver,markflorisson/python-driver,mobify/python-driver,thelastpickle/python-driver,mike-tr-adamson/python-driver,jfelectron/python-driver,coldeasy/python-driver,stef1927/python-driver,kracekumar/python-driver,stef1927/python-driver,mambocab/python-driver