Closes #340. Add warning when CASSANDRA_HOME is set in environment (#682)
Closes #340. Add warning when CASSANDRA_HOME is set in environment (#682)

* Add warning when CASSANDRA_HOME is set in environment

* re-rearranged module imports (with isort)

* Sort importing modules, observer PEP8

pcmanus/ccm,pcmanus/ccm,pcmanus/ccm