Release 0.0.7

This release introduces a new way of installing ghcup (and GHC and cabal in the process)
with the infamous `curl .. | sh` pattern. See #36 for discussion. This
is completely optional.

Features:

- Add a bootstrap-haskell script, fixes #36
- Allow to specify tags for `ghcup install`, `ghcup install-cabal` and `ghcup set`
- `ghcup list` also shows tags
- support installing on macOS aka Darwin
- Improve detection logic for CentOS/Alpine/AIX/FreeBSD
- Introduce a GHCUP_INSTALL_BASE_PREFIX env variable to control where `.ghcup` directory will be created
- Add rudimentary support for Amazon Linux

Bugfixes:

- Create missing haddock -> haddock-ghc symlink
- Emit distro-alias inferred in `debug-info` output
- Tweak exit code for `ghcup install` (If a GHC is already installed, we shouldn't treat it as an error)

Cleanups:

- Simplify mkdir calls
- Documentation improvements
- Error handling improvements

API changes:

- `self-update` was renamed to `upgrade`

Release 0.0.6

Release 0.0.5

Release 0.0.4

Release 0.0.3

Release 0.0.2

Release 0.0.1