Bump npm version -> 3.1.1
Bump npm version -> 3.1.1

Includes a fix for linux binaries on nodejs version 8.x. No source
changes.

laverdet/node-fibers,meteor/node-fibers,meteor/node-fibers,meteor/node-fibers,laverdet/node-fibers,laverdet/node-fibers,meteor/node-fibers,laverdet/node-fibers