Fix broken tests

[cjbarth]

There were two bugs in the code that were causing the tests to fail. Due to the way the tests were written tests failed as timeouts. I've also adjusted the tests so that when they fail they give useful information.

No functional changes were made to the test. The only changes were to correctly wrap async exception throwing blocks in a try...catch and then call done() properly so that mocha could properly report the error instead of having to wait 2 seconds for timeout and then reporting that instead of the actual error that occured.

[mlunoe]

Thank you for fixing this!
Tested it out and this works for me and tests pass and report errors as expected

[cjbarth]

As I was updating typings for v1.1 when it is released I found that there were some inconsistencies and metadata was being mishandled. Error handling was also broken.

I've corrected these issues in this PR as well.

[markstos]

This test does not appear to actually be async, so could be converted to a sync test without try/catch.

[markstos]

@cjbarth I see that's a lot of work that's been put here.

I'm reluctant to merge this because the try/catch syntax is verbose and ugly. I also understand that's solving a real problem with sync errors being thrown in async test.

Now that Node 6.x is EOL'ed, we can drop support for it, which means it's safe to start using async/await in the code base. This could help clean up the tests, but to take advantage of it we should also update some functions to return a promise if no callback is provided.

Still, I realize a release is overdue for for the moment I have gratitude that this fixes for the tests for now, so I'm merging it.