title: grunt command not found after installed grunt and grunt cli
body: <p>I installed grunt and grunt cli, but still I got command not found error</p>
  
  <pre><code>{
    "name": "angulartdd",
    "version": "1.0.0",
    "description": "1",
    "main": "index.js",
    "scripts": {
      "test": "echo \"Error: no test specified\" &amp;&amp; exit 1"
    },
    "author": "",
    "license": "ISC",
    "devDependencies": {
      "grunt-cli": "^1.2.0",
      "grunt-karma": "^2.0.0",
      "jasmine": "^2.5.2",
      "karma": "^1.3.0",
      "karma-jasmine": "^1.1.0"
    }
  }
  </code></pre>
  
  <p>I can try to install grunt globally but I want to know why this isn't working.</p>