Bug sorting

When I used [react-navigate](https://reactnavigation.org) TabBar Component with react-native-sortable-listview that list freezes when I bring the active element to the edge of the screen.

To solve the problem I use `disableAnimatedScrolling = {true}` for react-native-sortable-listview and `animationEnabled: false,` for [react-navigate](https://reactnavigation.org) but but for me animation is important.

the bug is present on ios and on Android works well.

code bug example:
where 'App' = [example for this library](https://github.com/deanmcpherson/react-native-sortable-listview/blob/master/Sortable)
```
const Tab = TabNavigator(
{
App: { screen: App,
navigationOptions: {
title: 'Home',
tabBarLabel: 'Home',
tabBarVisible: true,

}},
},
{
tabBarPosition: 'top',
tabBarComponent: TabBarTop,
animationEnabled: true,
swipeEnabled: false,
});

AppRegistry.registerComponent('sort', () => Tab);
```

checked on the following configurations:

```
"react": "16.0.0-alpha.12",
"react-native": "^0.48.4",
"react-navigation": "1.0.0-beta.11",
"react-native-sortable-listview": "^0.2.8",
```

and

```
"react": "16.2.0",
"react-native": "0.53.0",
"react-native-sortable-listview": "^0.2.8",
"react-navigation": "^1.0.3"
```

Start with the linked Sortable example and reproduce the freeze on iOS using the provided React Native and react-navigation configurations. Test dragging the active item to the screen edge with both animations enabled, then compare the Android behavior. Done means edge dragging no longer freezes while animation remains enabled.

Written by the indexing model from the issue text.