librarites-and-tools.md: add Scala-based maciej/etcd-client
librarites-and-tools.md: add Scala-based maciej/etcd-client

hongchaodeng/etcd,dnaeon/etcd,gyuho/etcd,StorReduce/etcd,swingbach/etcd,sebrandon1/etcd,rnaveiras/etcd,endocode/etcd,fanminshi/etcd,glycerine/etcd,purpleidea/etcd,mkumatag/etcd,rchicoli/etcd,glevand/coreos--etcd,bdarnell/etcd,plasticbox/etcd,westhood/etcd,mqliang/etcd,jonboulle/etcd,a-robinson/etcd,insequent/etcd,fanminshi/etcd,gyuho/etcd,dannysauer/etcd,wantonsolutions/dinv-etcd,akauppi/etcd,lumjjb/etcd,dannysauer/etcd,chipironcin/etcd,ajityagaty/etcd,li-ang/etcd,bluebreezecf/etcd,zaphod-concur/etcd,insequent/etcd,jlamillan/etcd,tguangch/etcd,heyitsanthony/etcd,YuleiXiao/etcd,sebrandon1/etcd,xiang90/etcd,plasticbox/etcd,qqsun8819/etcd,coreos/etcd,visheshnp/etcd,wantonsolutions/dinv-etcd,purpleidea/etcd,CrazyJvm/etcd,rnaveiras/etcd,yudai/etcd,linuxcer/etcd,lorneli/etcd,joshix/etcd,sofuture/etcd,vimalk78/etcd,joshix/etcd,whuwxl/etcd,lorneli/etcd,tguangch/etcd,ajityagaty/etcd,whuwxl/etcd,etcd-io/etcd,dnaeon/etcd,xiang90/etcd,ktateish/etcd,OyTao/etcd_learning,mkumatag/etcd,rchicoli/etcd,sofuture/etcd,qqsun8819/etcd,lumjjb/etcd,StorReduce/etcd,mqliang/etcd,li-ang/etcd,heyitsanthony/etcd,mqliang/etcd,ajityagaty/etcd,cockroachdb/etcd,endocode/etcd,bdarnell/etcd,visheshnp/etcd,etcd-io/etcd,mickep76/etcd,bluebreezecf/etcd,armstrongli/etcd,handsomesun/etcd,ravigadde/etcd,handsomesun/etcd,armstrongli/etcd,jonboulle/etcd,glevand/coreos--etcd,rnaveiras/etcd,ktateish/etcd,akauppi/etcd,YuleiXiao/etcd,sinsharat/etcd,a-robinson/etcd,etcd-io/etcd,chipironcin/etcd,OyTao/etcd_learning,yudai/etcd,luxas/etcd,glycerine/etcd,zaphod-concur/etcd,nekto0n/etcd,jlamillan/etcd,mkumatag/etcd,vimalk78/etcd,cockroachdb/etcd,hongchaodeng/etcd,nekto0n/etcd,sinsharat/etcd,ravigadde/etcd,CrazyJvm/etcd,wantonsolutions/dinv-etcd,luxas/etcd,mickep76/etcd,coreos/etcd,westhood/etcd,linuxcer/etcd,swingbach/etcd