title: ionic build android error (:transformClassesWithDexForDebug)
body: <p>Everything was fine and working perfectly till i execute the command "ionic build android"
  and then this error occurs.</p>
  
  <p>:transformClassesWithDexForDebugjava.lang.UnsupportedClassesVersionError: com.android.dx/command/Main : Unsupported Major.minor version 52.0</p>
  
  <p>and so on......</p>
  
  <p><a href="https://i.stack.imgur.com/PMumt.png" rel="noreferrer"><img src="https://i.stack.imgur.com/PMumt.png" alt="enter image description here"></a></p>