update lint packages, fix lint errors

Summary: @​cesarandreu pointed out running eslint on react-native resulted in `t.isReferencedIdentifier is not a function` issues on the babel #linting channel on slack.

- update eslint, babel-eslint, eslint-plugin-react
- fix eslint errors: `Error - t.isReferencedIdentifier is not a function`
- fix lint npm script

I see there's also https://github.com/facebook/react-native/pull/1736 from @ide which would fix it tooCloses https://github.com/facebook/react-native/pull/1874

Reviewed By: @vjeux

Differential Revision: D2495878

Pulled By: @frantic

package.json

@@ -38,7 +38,7 @@
   ],
   "scripts": {
     "test": "NODE_ENV=test jest",
-    "lint": "node linter.js Examples/ Libraries/",
+    "lint": "eslint Examples/ Libraries/",
     "start": "./packager/packager.sh || true"
   },
   "bin": {