Remove unused stop_cluster code.
Remove unused stop_cluster code.

Azulinho/flocker,1d4Nf6/flocker,adamtheturtle/flocker,AndyHuu/flocker,runcom/flocker,w4ngyi/flocker,agonzalezro/flocker,mbrukman/flocker,wallnerryan/flocker-profiles,adamtheturtle/flocker,wallnerryan/flocker-profiles,1d4Nf6/flocker,jml/flocker,adamtheturtle/flocker,lukemarsden/flocker,hackday-profilers/flocker,agonzalezro/flocker,mbrukman/flocker,Azulinho/flocker,wallnerryan/flocker-profiles,w4ngyi/flocker,lukemarsden/flocker,AndyHuu/flocker,achanda/flocker,hackday-profilers/flocker,LaynePeng/flocker,jml/flocker,LaynePeng/flocker,Azulinho/flocker,hackday-profilers/flocker,runcom/flocker,w4ngyi/flocker,runcom/flocker,moypray/flocker,moypray/flocker,AndyHuu/flocker,jml/flocker,achanda/flocker,LaynePeng/flocker,lukemarsden/flocker,1d4Nf6/flocker,mbrukman/flocker,agonzalezro/flocker,moypray/flocker,achanda/flocker