module.js:471
    throw err;
    ^

Error: Cannot find module 'underscore.string'
  at Function.Module._resolveFilename (module.js:469:15)
  at Function.Module._load (module.js:417:25)
  at Module.require (module.js:497:17)
  at require (internal/module.js:20:19)
  at Object.<anonymous> (/Users/maros/Google Drive/DEV/boiler projects/firebase_test/node_modules/grunt/node_modules/grunt-legacy-log/index.js:21:9)
  at Module._compile (module.js:570:32)
  at Object.Module._extensions..js (module.js:579:10)
  at Module.load (/Users/maros/Google Drive/DEV/boiler projects/firebase_test/node_modules/grunt/node_modules/coffee-script/lib/coffee-script/register.js:45:36)
  at tryModuleLoad (module.js:446:12)
  at Function.Module._load (module.js:438:3)
  at Module.require (module.js:497:17)
  at require (internal/module.js:20:19)
  at Object.<anonymous> (/Users/maros/Google Drive/DEV/boiler projects/firebase_test/node_modules/grunt/lib/grunt.js:21:38)
  at Module._compile (module.js:570:32)
  at Object.Module._extensions..js (module.js:579:10)
  at Module.load (module.js:487:32)
  at tryModuleLoad (module.js:446:12)
  at Function.Module._load (module.js:438:3)
  at Module.require (module.js:497:17)
  at require (internal/module.js:20:19)
  at Object.<anonymous> (/usr/local/lib/node_modules/grunt-cli/bin/grunt:44:1)
  at Module._compile (module.js:570:32)
  at Object.Module._extensions..js (module.js:579:10)
  at Module.load (module.js:487:32)
  at tryModuleLoad (module.js:446:12)
  at Function.Module._load (module.js:438:3)
  at Module.runMain (module.js:604:10)
  at run (bootstrap_node.js:394:7)
  at startup (bootstrap_node.js:149:9)
  at bootstrap_node.js:509:3