Complete properly placing placeholders where required

It seems like some more files did have this problem. I have done an extensive search and fix of all these files and this is my final submission.
There might be some parts still gone unnoticed as Python aparently doesn't consider the lack of placeholders an issue. No errors have popped up and tests work.

Author: de-sh

openapi_parser.py

@@ -235,7 +235,7 @@ def get_class_details(global_: Dict[str,
                                        write=True))
                 else:
                     global_[class_name]["prop_definition"].append(
-                        HydraClassProp("vocab:".format(prop), prop, required=flag,
+                        HydraClassProp("vocab:{}".format(prop), prop, required=flag,
                                        read=True, write=True))
             else:
                 global_[class_name]["prop_definition"].append(HydraClassProp(