Adding list data type to 'res' parameter of filter() function.

Adding list data type in addition to the existing str type to the 'res' and 'resolution' parameter of the filter() function of the StreamQuery class. This enables us to streams with multiple resolutions in a single query.

pytube/query.py

@@ -123,7 +123,10 @@ class StreamQuery(Sequence):
         """
         filters = []
         if res or resolution:
-            filters.append(lambda s: s.resolution == (res or resolution))
+            if isinstance(res, str) or isinstance(resolution, str):
+                filters.append(lambda s: s.resolution == (res or resolution))
+            elif isinstance(res, list) or isinstance(resolution, list):
+                filters.append(lambda s: s.resolution in (resolution or res))
 
         if fps:
             filters.append(lambda s: s.fps == fps)