message: [ci] Revert happy install workaround
  CI builds are failing with linker errors trying to install happy. This
  workaround no longer appears to be needed.
  Remove the manual install step.
diff: choco install haskell-stack -y
  - # temp workaround: install ghc for happy install
  -
  - choco install ghc --version 8.0.1 -y
  -
  choco install dotnetcore-sdk -y
  # choco install updated the path, so re-read them from the registry and reset $env:path
  $env:Path = "$machinePath;$userPath"
  - # temp workaround: run cabal update and install happy
  -
  - cabal update
  -
  - cabal install happy-1.19.5
  -
  if ($env:BOND_BUILD -eq "Doc") {
  choco install pandoc --version 1.19.2 -y
  