Changed version of React dependency to ~

Summary:
React has some internal code related only to React Native.
Some times React needs to update them which will result in a breaking change for React Native but it would not be a breaking change for React public API, so no major version bump will happen.
It means that a non breaking API bump may result in a break for React Native.
That is why React Native should not depend on a ^ of React version.

However React is a peer dependency to React Native and we want to give some flexibility to users to update React independently, so we don't fix the version strict and use ~ to allow patches.

This will be fixed once we extract RN specific code from React into an independent dependency.

Reviewed By: avaly

Differential Revision: D3398202

fbshipit-source-id: cca520f4b80c9ed5ae6fb1444f3d0bf7ffb9c9dd

package.json

@@ -125,7 +125,7 @@
     "react-native": "local-cli/wrong-react-native.js"
   },
   "peerDependencies": {
-    "react": "^15.1.0"
+    "react": "~15.1.0"
   },
   "dependencies": {
     "absolute-path": "^0.0.0",
@@ -201,7 +201,7 @@
     "flow-bin": "^0.26.0",
     "jest": "12.1.1",
     "portfinder": "0.4.0",
-    "react": "^15.1.0",
+    "react": "~15.1.0",
     "shelljs": "0.6.0"
   }
 }