Build with GHC-8.6.1

[chshersh]

No need to put on CI, but good to check locally at least.

[chshersh]

Library builds with ghc-8.6.1 but tasty fails to build.

[chshersh]

I've tested again. It now builds. But doctest fails. Because something has changed in base.

[vrom911]

I can't make it work. It seems not possible to build doctest without --allow-newer. Do you really think that it's a sane idea to put allow-newer?

[chshersh]

@vrom911 No, we're not going to build relude with allow-newer. It should be buildable without allow-newer. It's a pity that doctest doesn't build with ghc-8.6.1 😞

Maybe it makes sense to create issue in doctest to track the status of building with GHC-8.6.1.
Looks like build with ghc-8.6.1 for relude is delayed for better times...

[chshersh]

Tracking the status of the issue with doctest here:

• Support build with GHC 8.6.1 sol/doctest#207

[vrom911]

Okay, the next stop is stm. Seems it's going to be released soon (?).
haskell/stm#16

[vrom911]

Updates: the library is building now 🎉
The problem now is tests, more accurate – doctest library. I've opened the PR in there, but it's very hard to say if it will be approved (and work).

[chshersh]

@vrom911 Thanks for your effort! I hope that issue with doctest can be resolved soon... I would like to add support for GHC-8.6.1 to relude as soon as possible.