Add missing test for Predis\Client::getClientFor().
Add missing test for Predis\Client::getClientFor().

vend/predis,nrk/predis,RedisLabs/predis,zhangyancoder/predis,gopalindians/predis,moria/predis,protomouse/predis,oswaldderiemaecker/predis,stokes3452/predis,quangnguyen90/predis,mrkeng/predis,SecureCloud-biz/predis,dominics/predis,gencer/predis,nguyenthaihan/predis,CloudSide/predis,RudyJessop/predis,SwelenFrance/predis,dzung2t/predis,channelgrabber/predis,johnhelmuth/predis,WalterShe/predis,lvbaosong/predis