Improved schema validation

* Added debug Dockerfile/Makefile
* Validation of examples in docs

senpy/schemas/response.json

@@ -1,4 +1,9 @@
 {
   "$schema": "http://json-schema.org/draft-04/schema#",
-  "type": "object"
+  "type": "object",
+  "properties": {
+    "@type": {"type": "string"}
+  },
+  "required": ["@type"]
+
 }