Does not correctly read tsconfig since version 1.0.3

I have a tsconfig file which extends another, the extended file contains:

```
     "jsx": "react-jsx",
     "jsxImportSource": "*somelib*",
```

However since version 1.0.3 this setting is clearly being completely ignored (it tries to use ``React`` instead).

Manually pinning this package to 1.0.2 resolves the issue.
