* Remove outdated setup troubleshooting

* Remove ghc-8.6.4 support

* Remove ghc-8.10.2 support

* Remove ghc-8.10.3 support

* Remove ghc-8.10.4 support

* Complete list of tested ghcs

* Update stack resolvers

* Update hackage index

* Set 8.10.7 as default stack.yaml

* Use extra 1.7.9