Consider moving to TestNG?

[chrisengelsma]

Currently, we're using JUnit 4 as a our test package. It's great for simple testing, but TestNG allows for much more granularity for individual test settings, as well as native support for concurrent testing.

The structure and annotations for both are close enough that migrating would be relatively trivial I think and require a small bit of refactoring.

[chrisengelsma]

I've gone ahead and done the migration in my local fork, everything still works and now it zips along much faster now as it's testing in parallel on 5 threads. I will submit a PR unless anyone has a bleeding heart reason not to migrate.