Haskelloids does not build with ghc 8.4.4 and 8.6.1

[chriz-zeller]

Build logs

Reason:

Graphics/HGL/Internals/Events.hs:23:68: error:
    Module ‘Control.Concurrent.Chan’ does not export ‘isEmptyChan’

isEmptyChan is deprecated and is latest seen in base-4.10.1.0 (compare with base-4.11.0.0)

GHC 8.4 uses base 4.11.0.0

[Vincibean]

@chriz-zeller I tinkered a bit with the dependencies in #32 and the problem seems to be fixed.
Let me know if something else is needed.

[myroslambda]

@Vincibean I will be merging this one. I'll try it and let you know. Thank you!