The "latest" tag is a pain to maintain: it's a tag that we delete and
re-create at every release. Whenever we delete it, the binaries become
unavailable on Github until they are re-generated. Thus, from now on, we
conform to good practices (as examplified by the
github.com/docker/compose) project and distribute only pinned release.
The "nightly" tag remains, for now, as it allows us to distribute beta
features. It may disappear in the future.
Replace all make commands by a single "tutor" binary. Environment and
data are all moved to ~/.tutor/local/share/tutor. We take the
opportunity to add a web UI and revamp the documentation.
This is a complete rewrite.
Close #121.
Close #147.
