Fix ioTextWrapper buffer issue

Author: smlindauer

src/sasctl/_services/model_repository.py

@@ -403,7 +403,7 @@ def add_model_content(cls, model, file, name, role=None, content_type=None):
         if content_type is not None:
             files = {name: (name, file, content_type)}
         else:
-            files = {name: file}
+            files = {name: file.read()}
 
         metadata = {'role': role, 'name': name}