Change cassandra test per-core threadcount to 2
Change cassandra test per-core threadcount to 2

samanalysis/titan,samanalysis/titan,anuragkh/titan,infochimps-forks/titan,hortonworks/titan,mwpnava/titan,elkingtonmcb/titan,kalatestimine/titan,fengshao0907/titan,boorad/titan,jamestyack/titan,thinkaurelius/titan,tomersagi/titan,anuragkh/titan,elkingtonmcb/titan,anvie/titan,jankotek/titan,infochimps-forks/titan,pluradj/titan,tomersagi/titan,qiuqiyuan/titan,anvie/titan,xlcupid/titan,pluradj/titan,jankotek/titan,thinkaurelius/titan,twilmes/titan,kangkot/titan,jamestyack/titan,hortonworks/titan,evanv/titan,dylanht/titan,hortonworks/titan,nvoron23/titan,infochimps-forks/titan,kangkot/titan,anuragkh/titan,mbrukman/titan,qiuqiyuan/titan,dylanht/titan,amcp/titan,mwpnava/titan,CYPP/titan,mbrukman/titan,banjiewen/titan,samanalysis/titan,pluradj/titan,tomersagi/titan,elubow/titan,banjiewen/titan,anuragkh/titan,kalatestimine/titan,xlcupid/titan,amcp/titan,mwpnava/titan,hortonworks/titan,samanalysis/titan,anvie/titan,banjiewen/titan,ThiagoGarciaAlves/titan,ThiagoGarciaAlves/titan,twilmes/titan,mbrukman/titan,kalatestimine/titan,thinkaurelius/titan,xlcupid/titan,pluradj/titan,englishtown/titan,jamestyack/titan,mwpnava/titan,evanv/titan,banjiewen/titan,graben1437/titan,wangbf/titan,nvoron23/titan,nvoron23/titan,anuragkh/titan,jankotek/titan,kalatestimine/titan,amcp/titan,mwpnava/titan,evanv/titan,xlcupid/titan,jankotek/titan,jamestyack/titan,elkingtonmcb/titan,CYPP/titan,kangkot/titan,elkingtonmcb/titan,twilmes/titan,mbrukman/titan,ThiagoGarciaAlves/titan,nvoron23/titan,boorad/titan,thinkaurelius/titan,graben1437/titan,kangkot/titan,wangbf/titan,evanv/titan,anvie/titan,CYPP/titan,dylanht/titan,fengshao0907/titan,qiuqiyuan/titan,qiuqiyuan/titan,mbrukman/titan,qiuqiyuan/titan,fengshao0907/titan,evanv/titan,elubow/titan,infochimps-forks/titan,boorad/titan,ThiagoGarciaAlves/titan,infochimps-forks/titan,kalatestimine/titan,tomersagi/titan,hortonworks/titan,graben1437/titan,elkingtonmcb/titan,fengshao0907/titan,graben1437/titan,wangbf/titan,ThiagoGarciaAlves/titan,elubow/titan,amcp/titan,twilmes/titan,jankotek/titan,jamestyack/titan,elubow/titan,englishtown/titan,fengshao0907/titan,CYPP/titan,englishtown/titan,kangkot/titan,englishtown/titan,boorad/titan,xlcupid/titan,anvie/titan,twilmes/titan,tomersagi/titan,dylanht/titan,wangbf/titan,wangbf/titan