Fixing the issue on packager (failing with siblings error)

Summary:
The packager was failing with below error after a fresh clone

npm ERR! peerinvalid The package react@15.1.0 does not satisfy its siblings' peerDependencies requirements!

Changed the dependancy for **^react@15.1.0-alpha.1** to **^react@15.1.0** and it was fixed.
Closes https://github.com/facebook/react-native/pull/7692

Differential Revision: D3334425

fbshipit-source-id: ee86fc2e3c6f19b2430658d91d0a88c50bcf11de

package.json

@@ -124,7 +124,7 @@
     "react-native": "local-cli/wrong-react-native.js"
   },
   "peerDependencies": {
-    "react": "15.1.0-alpha.1"
+    "react": "15.1.0"
   },
   "dependencies": {
     "absolute-path": "^0.0.0",
@@ -191,7 +191,7 @@
     "flow-bin": "^0.25.0",
     "jest": "12.1.1",
     "portfinder": "0.4.0",
-    "react": "^15.1.0-alpha.1",
+    "react": "15.1.0",
     "shelljs": "0.6.0"
   }
 }