Use working GraphQL Playground version (#856)
Use working GraphQL Playground version (#856)

* Use working GraphQL Playground version

the linked file on jsDelivr doesn't work, as I detailed in this issue on the GraphQL Playground repo (https://github.com/graphql/graphql-playground/issues/1310). Going back to version 1.7.20 ensures the playground loads for now until they can publish a new version with a working middleware.js file.

* Add versions for css and favicon

* Update from 1.7.20 to 1.7.26

Using latest version that still works
graphql-rust/juniper,mhallin/juniper