Update version to 3.0.1

Only minor changes were made. The functionality
was not altered. The change is mainly for
solving inconveniences, update examples, ...

moochub-api.v3.yml

@@ -1,7 +1,7 @@
-openapi: 3.0.0
+openapi: 3.0.1
 info:
   title: MOOChub API
-  version: '3.0'
+  version: '3.0.1'
   description: API for MOOChub to access public course information.
   contact:
     name: openHPI

moochub-schema.json

@@ -1,6 +1,6 @@
 {
   "$schema": "https://json-schema.org/draft/2020-12/schema",
-  "$id": "https://github.com/moochub/schema/releases/tag/v3.0",
+  "$id": "https://github.com/moochub/schema/releases/tag/v3.0.1",
   "title": "JSON schema for MOOC providers integrated into moochub.org",
   "description": "This schema specifies the JSON format each MOOC provider must offer in order to be integrated into moochub.org",
   "type": "object",