Make integration test server_up? check more robust

The build keeps failing on Travis because the check to see that the server up isn't thorough enough. We also handle the case that WebMock is kind of screwing with Net::HTTP that we use legitimately in integration testing. Now everything works for me™. We'll see if this fixes it on Travis. Unfortunately, the problem is intermittent.

Having the automated tests fail when they should legitimately pass sucks.