Add in Middleware support.

[jcblw]

Right now we have a custom hook to add additional logging. I think this is fine but I think a more eloquent solution could be to use some sort of Middleware like outlined in this article.

https://link.medium.com/tq6FoquGQdb

[jcblw]

We can use the package referenced since we are already using make executable schema.

https://github.com/maticzav/graphql-middleware

[jcblw]

@arunsivasankaran I think this would allow us to have automatic light step tracing since there is some middleware for that.

[jcblw]

added!