transform rotate degree doesn't right when gives 45deg.
I am...Reporting a bug
-----

My code is:
```
const checks = StyleSheet.create({
  normal: {
    position: "relative",
    width: 16,
    height: 16,
    borderWidth: 1,
    borderColor: "#e6e8eb",
    borderRadius: 2,
    backgroundColor: "#fff",
  },
  marker: {
    width: 6,
    height: 10,
    position: "absolute",
    left: 4,
    top: 1,
    borderColor: 'white',
    borderBottomWidth: 2,
    borderRightWidth: 2,
    transform: 'rotate(45)'
  },
  checked: {
    borderColor: '#3370ff',
    backgroundColor: '#3370ff'
  }
});


<View style={[checks.normal, checks.checked]}>
  <View style={[checks.marker]}></View>
</View>

```
I expect the inside `View` will rotate 45deg counter-clock like this:

![image](https://user-images.githubusercontent.com/13088550/62541188-df6df100-b88b-11e9-8704-9386eb1b2172.png)

But I got this one:
![image](https://user-images.githubusercontent.com/13088550/62541246-03313700-b88c-11e9-9d5b-113ec93de2df.png)

The rotation attr in Sketch is shown as `-45`, not `45`.
I tired more degrees like 90, 180, etc, many of them wrong too.


the `react-sketchapp` version is `2.1.2` and Sketch's version is `56.3 (81716)`