title: .bin/authorize-ios not found when installing appium using npm install -g appium
body: <p>When I try to install appium using <code>npm install -g appium</code></p>
  <p>I get the message</p>
  <pre><code>npm ERR! code ENOENT
  npm ERR! syscall chmod
  npm ERR! path /usr/local/lib/node_modules/appium/node_modules/.bin/authorize-ios
  npm ERR! errno -2
  npm ERR! enoent ENOENT: no such file or directory, chmod '/usr/local/lib/node_modules/appium/node_modules/.bin/authorize-ios'
  npm ERR! enoent This is related to npm not being able to find a file.
  npm ERR! enoent
  </code></pre>
  <p>If I run the install again I get</p>
  <pre><code>npm ERR! code ENOENT
  npm ERR! syscall chmod
  npm ERR! path /usr/local/lib/node_modules/appium/build/lib/main.js
  npm ERR! errno -2
  npm ERR! enoent ENOENT: no such file or directory, chmod '/usr/local/lib/node_modules/appium/build/lib/main.js'
  npm ERR! enoent This is related to npm not being able to find a file.
  npm ERR! enoent
  </code></pre>
  <p>The first .bin/authorize-ios is indeed not there. I don't know how to fix it. When I install using <code>npm install appium-ios-driver</code> the driver is installed under <code>User/node_modules</code> and not at <code>usr/local/lib/node_modules</code>. I installed npm using brew.</p>