Allow int to pass aswell

Supports int, strings, list off ids.¨
This bugs like this happens when your watcking tv at the same time ¯\_(ツ)_/¯

plexapi/base.py

@@ -654,7 +654,7 @@ class Playable(object):
     def merge(self, ratingKeys):
         """Merge duplicate items."""
         if not isinstance(ratingKeys, list):
-            ratingKeys = ratingKeys.split(",")
+            ratingKeys = str(ratingKeys).split(",")
 
         key = '%s/merge?ids=%s' % (self.key, ','.join(ratingKeys))
         return self._server.query(key, method=self._server._session.put)