Add npm version

nodejs robot_server.js

module.js:356
  Module._extensions[extension](this, filename);
                               ^
Error: Module version mismatch. Expected 11, got 1.
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.<anonymous> (/home/anne/myworkspace/nodejs/zmqvideo/node_modules/zmq/lib/index.js:6:11)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)