Add badge for integration tests (#254)

Author: petea

.github/workflows/tests.yml renamed to .github/workflows/unit_tests.yml

@@ -1,4 +1,4 @@
-name: tests
+name: unit_tests
 
 on:
   push:

README.md

@@ -1,7 +1,8 @@
 [![Version](https://img.shields.io/cocoapods/v/GoogleSignIn.svg?style=flat)](https://cocoapods.org/pods/GoogleSignIn)
 [![Platform](https://img.shields.io/cocoapods/p/GoogleSignIn.svg?style=flat)](https://cocoapods.org/pods/GoogleSignIn)
 [![License](https://img.shields.io/cocoapods/l/GoogleSignIn.svg?style=flat)](https://cocoapods.org/pods/GoogleSignIn)
-[![tests](https://github.com/google/GoogleSignIn-iOS/actions/workflows/tests.yml/badge.svg?event=push)](https://github.com/google/GoogleSignIn-iOS/actions/workflows/tests.yml)
+[![unit_tests](https://github.com/google/GoogleSignIn-iOS/actions/workflows/unit_tests.yml/badge.svg?branch=main)](https://github.com/google/GoogleSignIn-iOS/actions/workflows/unit_tests.yml)
+[![integration_tests](https://github.com/google/GoogleSignIn-iOS/actions/workflows/integration_tests.yml/badge.svg?branch=main)](https://github.com/google/GoogleSignIn-iOS/actions/workflows/integration_tests.yml)
 
 # Google Sign-In for iOS and macOS