updating readme to reflect new Makefile changes
updating readme to reflect new Makefile changes

pagodabox/nanobox-docker-build,nanobox-io/nanobox-docker-build,pagodabox/nanobox-docker-build,nanobox-io/nanobox-docker-build,nanobox-io/nanobox-docker-build,nanobox-io/nanobox-docker-build