newer node on Travis, pre-build Dockerfile from tests dir
newer node on Travis, pre-build Dockerfile from tests dir

nuest/o2r-muncher,o2r-project/o2r-muncher,nuest/o2r-muncher,nuest/o2r-muncher,o2r-project/o2r-muncher,o2r-project/o2r-muncher,o2r-project/o2r-muncher,nuest/o2r-muncher,o2r-project/o2r-muncher,nuest/o2r-muncher