* tests: Add regression test for shellFor build-tools bug
* tests: Fix regen script
* Regenerate nix expressions for tests
* tests: ghc 8.4.4 -> 8.6.5
* shellFor: Fix bug where packages were not excluded from the env
If a multi-package project had an build-tools dependency between
packages, they would not be correctly removed from the shell's inputs.
* Use setup-depends from nix-tools output
* Use `-package ghc` when building Setup.hs
* Include --package-db when building Setup
* Fix for tests on case insensitive FS (macOS)
The file `conduit.hs` looks like `Conduit.hs` to ghc and it uses it
by mistake for `import Conduit`.