Disable npm's spinner

The spinner creates weird log output and the live view actually breaks pretty badly in a lot of cases.

Even though the latest version of npm only uses it on install (https://github.com/npm/npm/issues/5363), it still adds messiness.
can you add `, echo: false` to the end of this as well. I don't think we need to echo this to the log. You might need to update the spec as well.