Rename -s/--storm-cluster to -n/--nimbus-ip
Rename -s/--storm-cluster to -n/--nimbus-ip

This only changes the actual arguments; internally, "storm_cluster_ip" is
still in use.

Closes PYLEUS-150

poros/pyleus,jirafe/pyleus,poros/pyleus,patricklucas/pyleus,jirafe/pyleus,imcom/pyleus,ecanzonieri/pyleus,dapuck/pyleus,mzbyszynski/pyleus,Yelp/pyleus,patricklucas/pyleus,Yelp/pyleus,ecanzonieri/pyleus,dapuck/pyleus,stallman-cui/pyleus,imcom/pyleus,imcom/pyleus,stallman-cui/pyleus,mzbyszynski/pyleus