title: Mapbox doesn't work in fragment
body: <p>I put mapbox in fragment but I can only see the title. Here is my code in fragment.</p>
  
  <p>I can only see a gray screen with mapbox title. And I got no errors except emulator. Also, I tried to get Instance of MapBox in parent activity but it doesn't work either. I could sure use some help.</p>
  
  <pre><code>public class MapBox extends Fragment
  {
      View root;
      MapView mapView;
  
  
      @Override
      public void onCreate(@Nullable Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
      }
  
      @Nullable
      @Override
      public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
  
          Mapbox.getInstance(getContext(),
                  "pk.eyJ1IjoiYWNpaGFuayIsImEiOiJjamRobGVpdjUwd2tpMndtZmpsemxybjBjIn0.dmYB5bqnEqC57WqfH06hIQ");
          root = inflater.inflate(R.layout.mapbox_layout, container, false);
  
          return  root;
      }
  
      @Override
      public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
  
          mapView =(MapView) (root).findViewById(R.id.mapboxView);
          mapView.onCreate(savedInstanceState);
      }
  
      @Override
      public void onStart() {
          super.onStart();
          mapView.onStart();
      }
  
      @Override
      public void onResume() {
          super.onResume();
          mapView.onResume();
      }
  
      @Override
      public void onPause() {
          super.onPause();
          mapView.onPause();
      }
  
      @Override
      public void onStop() {
          super.onStop();
          mapView.onStop();
      }
  
      @Override
      public void onLowMemory() {
          super.onLowMemory();
          mapView.onLowMemory();
      }
      @Override
      public void onDestroy() {
          super.onDestroy();
          mapView.onDestroy();
      }
  
      @Override
      public void onSaveInstanceState(Bundle outState) {
          super.onSaveInstanceState(outState);
  
      }
  }
  </code></pre>