Just upgraded to 2.3. Then cannot open `graphql` site anymore. It shows `graphiql.js` file not found. <img width="520" alt="Screen Shot 2019-06-19 at 11 10 41 PM" src="https://user-images.githubusercontent.com/22938626/59825159-155d1300-92e8-11e9-8cf7-3542a1a4a4dd.png"> <img width="358" alt="Screen Shot 2019-06-19 at 11 14 18 PM" src="https://user-images.githubusercontent.com/22938626/59825166-1db54e00-92e8-11e9-8675-e5397b7b5e18.png"> #683 looks similar to my issue, but I can't pull up the site with what @brandonmbanks did.