Merge pull request #725 from andersk/body-default

Fix `MockRequest.body` type

Author: p1c2u

openapi_core/testing/requests.py

@@ -31,7 +31,7 @@ def __init__(
         self.view_args = view_args
         self.headers = headers
         self.cookies = cookies
-        self.body = data or ""
+        self.body = data or b""
         self.content_type = content_type
 
         self.parameters = RequestParameters(