Add validate handler

app.py

@@ -68,6 +68,21 @@ class Oas3Handler(tornado.web.RequestHandler, metaclass=ABCMeta):
         self.finish()
 
 
+class ValidateHandler(tornado.web.RequestHandler, metaclass=ABCMeta):
+    def post(self):
+        self.set_header("Content-Type", "application/json")
+
+        entity = self.request.body.decode()
+
+        # TODO call validator
+        validation_result = {
+            "valid": "true"
+        }
+
+        self.write(validation_result)
+        self.finish()
+
+
 def make_app():
     version_path = r"/v[0-9]"
     return tornado.web.Application([