Fixed titan-cassandra pom.xml typo
Fixed titan-cassandra pom.xml typo

<scope>optional</scope> is not valid.  I intended
<optional>true</optional>.  This changed accordingly.

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