Add haskell/monad-unify

Signed-off-by: Ricky Elrod <ricky@elrod.me>
Add haskell/pattern-arrows

Signed-off-by: Ricky Elrod <ricky@elrod.me>
Add haskell/purescript :D

Signed-off-by: Ricky Elrod <ricky@elrod.me>
Merge pull request #2768 from CodeBlock/purescript

Purescript + deps