Scalar Upload generated type from graphql-binding as a string
![2018-08-15-143201_1310x96_escrotum](https://user-images.githubusercontent.com/25862154/44136782-4a5c055e-a098-11e8-8995-9b8af521fa6b.png)

is it suppose to be like this below?
```typescript
export type Upload = {
      stream: NodeJS.ReadableStream
      filename: string
      mimtype: string
      encoding: string
}
```