Adam Gorman

``` \node_modules\react-native-windows\PropertySheets\External\Microsoft.ReactNative.Uwp.CppLib.targets(12,5): warning MSB4011: "\node_modules\react-native-windows\Microsoft.ReactNative.Cxx\Microsoft.ReactNative.Cxx.vcxitems" cannot be imported again. It was already imported at "\node_modules\@react-native-community\slider\windows\SliderWindows\SliderWindows.vcxproj (80,5)". This is most likely a build authoring error. This subsequent import will be ignored....