Procfile: change it to double-dash in Procfile
Procfile: change it to double-dash in Procfile

This makes flags to etcdmain consistent with man page in help.go. The standard
Go flag package supports both '-' and '--', different than most of CLI
packages, but etcdctl with codegansta/cli uses double-dash('--'), which
sometimes gets confusing, especially to new users.

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