Fix Ubuntu build instructions.
Fix Ubuntu build instructions.

nabilzhang/enunciate,nabilzhang/enunciate,uniqueid001/enunciate,nabilzhang/enunciate,nabilzhang/enunciate,garyhodgson/enunciate,garyhodgson/enunciate,uniqueid001/enunciate,garyhodgson/enunciate,garyhodgson/enunciate,uniqueid001/enunciate,nabilzhang/enunciate,uniqueid001/enunciate,uniqueid001/enunciate,nabilzhang/enunciate,garyhodgson/enunciate,garyhodgson/enunciate,garyhodgson/enunciate,uniqueid001/enunciate,garyhodgson/enunciate,nabilzhang/enunciate,uniqueid001/enunciate,uniqueid001/enunciate