Fixes terminate_idle_job_flows

terminate_idle_job_flows would crash if the conf path was provided as a command line arguement. This was because the previous fix to terminate_idle_job_flows was putting conf_paths in to a list.
The fix was to use conf_paths instead of conf_path.
Merge pull request #614 from sudarshang/fix_terminate_idle_flows_bugs

Fixes terminate_idle_job_flows