Adopt GitHub Actions as CI

[ethercrow]

I also switched stack-nightly.yaml to one that has GHC-8.10.1.

[ethercrow]

Current status: confused by

[14 of 34] Compiling Network.Wai.Handler.Warp.HTTP2.Types ( Network/Wai/Handler/Warp/HTTP2/Types.hs, dist/build/Network/Wai/Handler/Warp/HTTP2/Types.o )

Network/Wai/Handler/Warp/HTTP2/Types.hs:10:1: error:
    Could not find module ‘Network.HTTP2.Server’
    Perhaps you meant
      Network.HTTP2.Decode
      Network.HTTP2.Types
    Use -v (or `:set -v` in ghci) to see a list of the files searched for.
   |
10 | import qualified Network.HTTP2.Server as H2
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[lucasdicioccio]

Hi, thanks for putting this effort! GitHub Actions are entirely new to me.

The error you see looks like an error in warp or warp-tls (maybe under some flags). I have some time tomorrow to look-it up.

[lucasdicioccio]

The issue seems to be with wai >= 3.2.0 having moved the internal HTTP2 server (into the http2 >= 2.0.0 package).