Weird, even before the scl refactor, we only installed npm on Fedora [1]. Probably couldn't hurt to have it though.

[1]: https://github.com/openshift/origin-server/blob/dedcea1f01fe869bed4fb8c685e8e69806f5197a/cartridges/openshift-origin-cartridge-nodejs/openshift-origin-cartridge-nodejs.spec#L24