Added composer requirement for pusher/pusher

Author: jacurtis

composer.json

@@ -9,7 +9,8 @@
         "fideloper/proxy": "~3.3",
         "laravel/framework": "5.5.*",
         "laravel/socialite": "^3.0",
-        "laravel/tinker": "~1.0"
+        "laravel/tinker": "~1.0",
+        "pusher/pusher-php-server": "^3.0"
     },
     "require-dev": {
         "filp/whoops": "~2.0",