add error handling to create_user function

Author: sszepe

dspace_rest_client/client.py

@@ -1335,9 +1335,16 @@ def create_user(self, user, token=None, embeds=None):
         params = parse_params(embeds=embeds)
         if token is not None:
             params = {"token": token}
-        return User(
-            api_resource=parse_json(self.create_dso(url, params=params, data=data))
-        )
+
+        api_resource = self.create_dso(url, params=params, data=data)
+        if api_resource.status_code == 201 and api_resource.text:
+            return User(api_resource=parse_json(api_resource))
+        elif api_resource.status_code in [400, 401, 403, 422]:
+            logging.error("User creation failed: %s", api_resource.text)
+            return None
+        else:
+            logging.error("User creation failed: %s", api_resource.text)
+            return None
 
     def delete_user(self, user):
         if not isinstance(user, User):