Comment out GHC 8.4 on appveyor for now (#313)
Comment out GHC 8.4 on appveyor for now (#313)

commercialhaskell/intero,commercialhaskell/intero,chrisdone/intero,commercialhaskell/intero,chrisdone/intero,chrisdone/intero,chrisdone/ghci-ng,chrisdone/ghci-ng