Use db:migrate instead of schema:load since destructive action fails

app.json

@@ -22,7 +22,7 @@
     }
   },
   "scripts": {
-    "postdeploy": "bundle exec rake db:schema:load db:seed"
+    "postdeploy": "bundle exec rake db:migrate db:seed"
   },
   "stack": "heroku-18"
 }