feat: update pouchdb-push with user doc diff support

Author: Johannes J. Schmidt

package.json

@@ -36,7 +36,7 @@
   "dependencies": {
     "async": "^1.5.0",
     "couchdb-configure": "^1.5.0",
-    "couchdb-push": "^2.2.2",
+    "couchdb-push": "^2.3.0",
     "couchdb-secure": "^1.4.1",
     "glob": "^6.0.1",
     "minimist": "^1.2.0",