chore(NPM): bump version to 0.31.3

Includes cherry-picked commits for timer bug fix and run-windows bug fix.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-native-windows",
-  "version": "0.31.2",
+  "version": "0.31.3",
   "description": "React Native platform extensions for the Universal Windows Platform.",
   "license": "MIT",
   "repository": {