Make "make" equivalent to "make help", just like rietveld.py behaves.
Make "make" equivalent to "make help", just like rietveld.py behaves.

nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,nicko96/Chrome-Infra,riannucci/rietveldv2,nicko96/Chrome-Infra,riannucci/rietveldv2