Haskell bindings for the Slack web API

Example

> import qualified Web.Slack as Slack

> import qualified Web.Slack.Api as Api

> manager <- Slack.mkManager

> :set -XRecordWildCards
> Slack.Cli{..} = Slack.mkCli
apiTest :: ...
authTest :: ...
channelsCreate :: ...
chatPostMessage :: ...

> Slack.run manager (apiTest Api.mkTestReq)
Right ...

> :set -XOverloadedStrings
> Slack.run manager (apiTest Api.mkTestReq { testReqFoo = Just "bar" })
Right ...