export_test.go example

This go module demonstrates the power of export_test.go.

The athena package wraps the Athena SDK provided by the laborious AWS Go SDK.

On wrapping the AWS glue client

If I were to do this again - I would avoid wrapping the AWS glue client in a struct for a single method (or perhaps even multiple methods), instead opting to use a function that receives a glue client interface parameter.

I can still mock, but wouldn't need to bother with export_test.go idiom at all.

But the example still serves the purpose of demonstrating how it is used.