title: Ionic 2: error while running on Android platform
body: <p>I'm using Ionic 2 when I used the command <code>ionic cordova run android</code> I had this error:</p>
  
  <pre><code>Fetching plugin "mx.ferreyra.callnumber@~0.0.2" via npm
  ERROR running one or more of the platforms: Android SDK not found. 
  Make sure that it is installed. If it is not at the default location, 
  set the ANDROID_HOME environment variable. 
  You may not have the required environment or OS to run this project.
  </code></pre>
  
  <p>Can anyone tell me the solution? </p>