Graphql version conflict

[digital-stoic]

Hi,

example.js does not work anymore. Here is the error message from GraphiQL interface:

{
  "errors": [
    {
      "message": "Schema must be an instance of GraphQLSchema. Also ensure that there are not multiple versions of GraphQL installed in your node_modules directory."
    }
  ]
}

It seems to be due to the different versions required by joiql and express-graphql packages