Jorwoods/type hint groups (#938)

* Type hint groups

* Type hint GroupRequest

Co-authored-by: Jac <jacalata@users.noreply.github.com>

Author: jorwoods

tableauserverclient/server/request_factory.py

@@ -23,7 +23,6 @@
     from ..models import FlowItem
     from ..models import ConnectionItem
 
-
 def _add_multipart(parts: Dict) -> Tuple[Any, str]:
     mime_multipart_parts = list()
     for name, (filename, data, content_type) in parts.items():