Update to 3.1

CHANGELOG:
3.1
* More instances for `Coproduct`

3.0.4
* Removed unnecessary constraints in `Control.Comonad.Trans.Store`.

3.0.3
* Marked modules Trustworthy as needed.

3.0.2
* Merge pull request https://github.com/ekmett/comonad-transformers/issues/1
    made this GHC 7.8-ready

3.0.1
* Removed upper bounds on my other dependencies
* Directory layout change
* Added support files
* Travis build notification to IRC

3.0.0.1
* dep bump

3.0
* Upgraded to comonad 3.0
* Upgraded to semigroupoids 3.0

2.1.2
* Added experiment

2.1.1.1
* dep bump

2.1.1
* allow compatibility with the haskell platform

2.1
* Removed Discont
* Switched to mkTyCon3
* Upgraded to transformers 0.3

2.0.3
* dep bump
Import comonads-fd-3.0.3 as wip/hs-comonads-fd.

Comonad transformers using functional dependencies
Import comonads-fd-3.0.3 as wip/hs-comonads-fd.