[WIP] Swagger instance for UVerb.

[fisx]

No description provided.

[akhesaCaro]

Hi,
Servant-swagger will be moved into the main Servant repo (see : haskell-servant/servant#1475)
If this issue is still relevant, would it be possible for you to rebase on that repo (when it will be merged)? : https://github.com/haskell-servant/servant/

Thanks in advance!