More unit tests on request log behavior.

Trying to track down a scenario where production logs show commands executed apparently with no events (as if from cache).

Here is an example from production logs:

PlaylistGet[Executed][0ms]x3, PlaylistGet[SUCCESS][0ms], ViewingHistoryGetViewingHistory[Executed][0ms]x3, ViewingHistoryGetViewingHistory[SUCCESS][0ms]

Note the "Executed" which is a placeholder when no event exists.

So far I have not been able to replicate via unit tests.
UnitTest for Checked Exceptions

Adding a unit test for behavior added in https://github.com/Netflix/Hystrix/pull/64 and discussed in https://github.com/Netflix/Hystrix/issues/63
Merge pull request #67 from benjchristensen/unit-tests

Unit tests for checked exceptions and requests logs.