release 3.1.0

35a4fe0 readme: update doc for `registerVoipToken` will fire cached token  ( zxcpoiu 2021-01-15 19:03:13 +0800)
bb5485b remove unused import  ( zxcpoiu 2021-01-15 18:44:22 +0800)
3d1b675 cache lastVoipToken and return it when subsequently call to registerVoipToken  ( zxcpoiu 2021-01-15 18:15:55 +0800)
ab54fd9 readme: update usage doc add some notes  ( zxcpoiu 2020-12-08 16:16:07 +0800)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-native-voip-push-notification",
-  "version": "3.0.0",
+  "version": "3.1.0",
   "description": "VoIP push notification on react-native",
   "main": "index.js",
   "scripts": {