Same as resin-io-modules/resin-settings-storage#22.
Though the build works on circle, the deploy step currently fails on a couple of these modules because they require npm >= 4, as they use prepublishOnly, and the default npm version for node 6 is npm 3.
This PR makes sure we always use npm 4 all the way through, which should solve that (though I can't test it fully until this is merged).
Same as resin-io-modules/resin-settings-storage#22.
Though the build works on circle, the deploy step currently fails on a couple of these modules because they require npm >= 4, as they use prepublishOnly, and the default npm version for node 6 is npm 3.
This PR makes sure we always use npm 4 all the way through, which should solve that (though I can't test it fully until this is merged).