create-native-app throws error.

here's the error.

```
npm run create-native-app native

> @ create-native-app /Users/necmettinkarakaya/Projects/workspace
> react-workspace-scripts create-native-app "native"

Creating native app Native at ./native
Installing dependencies, this may take a minute.
events.js:160
throw er; // Unhandled 'error' event
^

Error: spawn react-native ENOENT
at exports._errnoException (util.js:1018:11)
at Process.ChildProcess._handle.onexit (internal/child_process.js:193:32)
at onErrorNT (internal/child_process.js:367:16)
at _combinedTickCallback (internal/process/next_tick.js:80:11)
at process._tickCallback (internal/process/next_tick.js:104:9)
at Module.runMain (module.js:606:11)
at run (bootstrap_node.js:389:7)
at startup (bootstrap_node.js:149:9)
at bootstrap_node.js:504:3
```