Merge pull request #199 from espresso3389/master

Realank#197 shadowThemeOnly is removed on flutter master

lib/flutter_datetime_picker.dart

@@ -212,11 +212,7 @@ class _DatePickerRoute<T> extends PopupRoute<T> {
         pickerModel: pickerModel,
       ),
     );
-    ThemeData inheritTheme = Theme.of(context);
-    if (inheritTheme != null) {
-      bottomSheet = new Theme(data: inheritTheme, child: bottomSheet);
-    }
-    return bottomSheet;
+    return InheritedTheme.captureAll(context, bottomSheet);
   }
 }