use entity validator in app

app.py

@@ -12,6 +12,7 @@ import json
 
 import util
 
+from entity_validator import validate
 
 startup_timestamp = datetime.now()
 
@@ -74,12 +75,9 @@ class ValidateHandler(tornado.web.RequestHandler, metaclass=ABCMeta):
 
         entity = self.request.body.decode()
 
-        # TODO call validator
-        validation_result = {
-            "valid": "true"
-        }
+        validation_result = validate(json.loads(entity))
 
-        self.write(validation_result)
+        self.write(json.dumps(validation_result))
         self.finish()