Cluster regression test for #3043.
Cluster regression test for #3043.

The test works but is very slow so far, since it involves resharding
1/5 of all the cluster slots from master 0 to the other 4 masters and
back into the original master.

dreamquster/redis,rogerchina/redis,kensou97/redis,yossigo/redis,oranagra/redis,pmem/redis,neomantra/redis,yossigo/redis,colstrom/redis,YongMan/redis,GitHubMota/redis,Markgorden/redis,ctripcorp/redis,PKRoma/redis,oranagra/redis,ctripcorp/redis,sunheehnus/redis,charsyam/redis,h0x91b/redis,dreamquster/redis,badboy/redis,PKRoma/redis,nnog/redis,badboy/redis,antirez/redis,arijitvt/redis,spinlock/redis,badboy/redis,Markgorden/redis,h0x91b/redis,hgl888/redis,ofirluzon/redis,YongMan/redis,Sciumo/redis,charsyam/redis,hgl888/redis,Sciumo/redis,soloestoy/redis,rogerchina/redis,oranagra/redis,GitHubMota/redis,GitHubMota/redis,oranagra/redis,zguangyu/redis,antirez/redis,nnog/redis,nnog/redis,neomantra/redis,sunheehnus/redis,charsyam/redis,neomantra/redis,ctripcorp/redis,ofirluzon/redis,ofirluzon/redis,zguangyu/redis,soloestoy/redis,charsyam/redis,soloestoy/redis,ton31337/redis,hgl888/redis,antirez/redis,rogerchina/redis,Sciumo/redis,oranagra/redis,Sciumo/redis,soloestoy/redis,Markgorden/redis,h0x91b/redis,Markgorden/redis,dreamquster/redis,h0x91b/redis,OmarQunsul/graph-redis,zguangyu/redis,OmarQunsul/graph-redis,ofirluzon/redis,soveran/redis,YongMan/redis,sunheehnus/redis,PKRoma/redis,nnog/redis,ofirluzon/redis,kensou97/redis,ton31337/redis,arijitvt/redis,arijitvt/redis,charsyam/redis,yossigo/redis,arijitvt/redis,kensou97/redis,ton31337/redis,pmem/redis,OmarQunsul/graph-redis,soveran/redis,neomantra/redis,spinlock/redis,soloestoy/redis,colstrom/redis,hgl888/redis,badboy/redis,pmem/redis,OmarQunsul/graph-redis,ctripcorp/redis,antirez/redis,zguangyu/redis,neomantra/redis,kensou97/redis,ton31337/redis,rogerchina/redis,colstrom/redis,GitHubMota/redis,spinlock/redis,PKRoma/redis,colstrom/redis,YongMan/redis,PKRoma/redis,sunheehnus/redis,pmem/redis,spinlock/redis,soveran/redis,yossigo/redis,dreamquster/redis,yossigo/redis,soveran/redis