Add branch alias

Author: mpociot

composer.json

@@ -16,7 +16,7 @@
     ],
     "require": {
         "php": ">=7.0",
-        "botman/botman": "~2.0",
+        "botman/botman": "~2.0|~3.0",
         "guzzlehttp/guzzle": "~6.0",
         "illuminate/support": "~5.5.0|~5.6.0",
         "illuminate/contracts": "~5.5.0|~5.6.0",