title: Cordova build require SDK Platform
body: <p>I'm on Ubuntu, I installed cordova, cordova cli, android studio and all the packages but when I try to build my app I recive the following error:</p>
  
  <pre><code>Running command: /home/admin/Desktop/hello/platforms/android/cordova/build 
  [Error: Please install Android target: "android-21".
  
  Hint: Open the SDK manager by running: /opt/android-sdk/tools/android
  You will require:
  1. "SDK Platform" for android-21
  2. "Android SDK Platform-tools (latest)
  3. "Android SDK Build-tools" (latest)]
  ERROR building one of the platforms: Error: /home/admin/Desktop/hello/platforms/android/cordova/build: Command failed with exit code 2
  You may not have the required environment or OS to build this project
  Error: /home/admin/Desktop/hello/platforms/android/cordova/build: Command failed with exit code 2
      at ChildProcess.whenDone (/usr/local/lib/node_modules/cordova/node_modules/cordova-lib/src/cordova/superspawn.js:131:23)
      at ChildProcess.EventEmitter.emit (events.js:98:17)
      at maybeClose (child_process.js:743:16)
      at Process.ChildProcess._handle.onexit (child_process.js:810:5)
  </code></pre>
  
  <p>Note: I added the path for android-sdk in bashrc:</p>
  
  <pre><code>#AndroidDev PATH
  
  export PATH=${PATH}:${HOME}/android-sdk-linux/tools
  
  export PATH=${PATH}:${HOME}/android-sdk-linux/platform-tools
  </code></pre>