refactor

lib/android/app/src/main/java/com/reactnativenavigation/NavigationActivity.java

 import android.view.KeyEvent;
 
 import com.facebook.react.modules.core.DefaultHardwareBackBtnHandler;
-import com.reactnativenavigation.layout.Navigator;
+import com.reactnativenavigation.viewcontrollers.Navigator;
 
 public class NavigationActivity extends AppCompatActivity implements DefaultHardwareBackBtnHandler {
 	private Navigator navigator;

lib/android/app/src/main/java/com/reactnativenavigation/react/NavigationModule.java

 import com.reactnativenavigation.parse.JSONParser;
 import com.reactnativenavigation.parse.LayoutNodeParser;
 import com.reactnativenavigation.utils.UiThread;
-import com.reactnativenavigation.layout.Navigator;
+import com.reactnativenavigation.viewcontrollers.Navigator;
 import com.reactnativenavigation.viewcontrollers.ViewController;
 
 public class NavigationModule extends ReactContextBaseJavaModule {

lib/android/app/src/main/java/com/reactnativenavigation/layout/Navigator.java → lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/Navigator.java

-package com.reactnativenavigation.layout;
+package com.reactnativenavigation.viewcontrollers;
 
 import android.app.Activity;
 import android.support.annotation.NonNull;
 import android.widget.FrameLayout;
 
 import com.reactnativenavigation.utils.CompatUtils;
-import com.reactnativenavigation.viewcontrollers.ParentController;
-import com.reactnativenavigation.viewcontrollers.StackController;
-import com.reactnativenavigation.viewcontrollers.ViewController;
 
 import java.util.Collection;
 import java.util.Collections;

lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/NavigatorTest.java

 import android.support.annotation.NonNull;
 
 import com.reactnativenavigation.BaseTest;
-import com.reactnativenavigation.layout.Navigator;
 import com.reactnativenavigation.mocks.SimpleViewController;
 import com.reactnativenavigation.mocks.TestStackAnimator;
 import com.reactnativenavigation.utils.CompatUtils;