[global-cli] Bump version to 0.1.9

To release a new version with the fix for Windows:
https://github.com/facebook/react-native/pull/5171

Thanks a lot @tdzl2003!

Tweaked the platform check to use `process.platform`
as that's more common in the codebase. No strong preference,
just for consistency.

react-native-cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-native-cli",
-  "version": "0.1.8",
+  "version": "0.1.9",
   "license" : "BSD-3-Clause",
   "description": "The React Native CLI tools",
   "main": "index.js",