Applicative instance of ExceptT is wrong

I've recently discovered a flaw in the Applicative and Alternative instances of EitherT. I've posted the following pull request to fix them: https://github.com/ekmett/either/pull/38 The pull request contains the description of the problem. ExceptT of "transformers" contains exactly the same flaw. However it's not hosted on GitHub, so I don't know a better place to report the issue then here. Best regards, Nikita Volkov