title: App crash in release build for enabling proguard when using GreenDao
body: <p>I am using GreenDao in my project, when I build the application in release mode then the app crashes. If I disable proguard (<code>minifyEnabled false</code>) in gradle then it's running perfectly. I have used the following rules in proguard.</p>
  
  <pre><code>### greenDAO 3
  -keepclassmembers class * extends org.greenrobot.greendao.AbstractDao {
  public static java.lang.String TABLENAME;
  }
  -keep class **$Properties
  
  # If you do not use SQLCipher:
  -dontwarn org.greenrobot.greendao.database.**
  # If you do not use RxJava:
  -dontwarn rx.**
  </code></pre>
  
  <p><strong>The error log is as follows:</strong></p>
  
  <pre><code>java.lang.RuntimeException: org.greenrobot.greendao.DaoException: Could not init DAOConfig
          at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3086)
          at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3229)
          at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
          at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
          at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1926)
          at android.os.Handler.dispatchMessage(Handler.java:106)
          at android.os.Looper.loop(Looper.java:214)
          at android.app.ActivityThread.main(ActivityThread.java:6981)
          at java.lang.reflect.Method.invoke(Native Method)
          at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1445)
  </code></pre>
  
  <p>Do you have any idea why this error occurs? Thanks in advance.</p>