Sandstorm fix for Meteor 1.6.0.1

sandstorm.js

@@ -22,7 +22,7 @@ const sandstormBoard = {
 
 if (isSandstorm && Meteor.isServer) {
   const fs = require('fs');
-  const Capnp = require('capnp');
+  const Capnp = require("/node_modules/capnp.js");
   const Package = Capnp.importSystem('sandstorm/package.capnp');
   const Powerbox = Capnp.importSystem('sandstorm/powerbox.capnp');
   const Identity = Capnp.importSystem('sandstorm/identity.capnp');