Replaced MonadCatchIO with exceptions and relaxed some dependencies

Hi,

So, currently MonadCatchIO-transfomers is [marked deprecated](http://hackage.haskell.org/package/MonadCatchIO-transformers), recommending the use of [exceptions](https://hackage.haskell.org/package/exceptions) instead. I've made (what I believe are) the necessary changes.

I've also relaxed some depencies to match the latest version of some packages... I've gone through their changelog and nothing relevant seems to have changed.

Please let me know if you are ok with these changes (and the proposed new version).

Cheers