Stores the _PushStatus when sending push, set pending, and running states

src/cryptoUtils.js

@@ -1,6 +1,6 @@
 /* @flow */
 
-import { randomBytes } from 'crypto';
+import { randomBytes, createHash } from 'crypto';
 
 // Returns a new random hex string of the given even size.
 export function randomHexString(size: number): string {
@@ -44,3 +44,7 @@ export function newObjectId(): string {
 export function newToken(): string {
   return randomHexString(32);
 }
+
+export function md5Hash(string: string): string {
+  return createHash('md5').update(string).digest('hex');
+}