Fix workflow and python syntax issues

.github/workflows/deploy-demo.yml

@@ -1,7 +1,8 @@
 name: Deploy to demo environment
 
 on:
-  push: [ production ]
+  push:
+    branches: [ production ]
 
 permissions:
   contents: read

app/config.py

@@ -415,9 +415,11 @@ class Production(Config):
 class Staging(Production):
     pass
 
+
 class Demo(Production):
     pass
 
+
 configs = {
     'development': Development,
     'test': Test,