Signed-off-by: Bastian Krause <bst@pengutronix.de>

`git describe` will fail if no tags are available. This happens with
clones without tags, e.g. `git clone --no-tags [...]`, forks without
tags and is the default of actions/checkout@v4 [1].

Add the `--always` option to `git describe` to show the "uniquely
abbreviated commit object as fallback" [2].

[1] https://github.com/actions/checkout/blob/v4/README.md#usage
[2] https://git-scm.com/docs/git-describe#Documentation/git-describe.txt---always

Signed-off-by: Bastian Krause <bst@pengutronix.de>

Since tox 4, "packaging environments no longer inherit their settings
from the testenv section" [1]. This becomes an issue for flamingo
because the environment variable FLAMINGO_TEST is checked in its
setup.py.

Fix this by moving the setenv directive to the build environment
section. passenv= in flamingo is not affected because other env lookups
are performed outside of its setup.py.

[1] https://tox.wiki/en/4.11.3/upgrading.html#packaging-configuration-and-inheritance

Signed-off-by: Bastian Krause <bst@pengutronix.de>

Testing with Python 3.6 has been dropped a while ago, while Python 3.10
testing was added. Advertise these versions and adjust the tox
environments accordingly.

Fixes: ae476f3 (".travis: Python versions update")
Signed-off-by: Bastian Krause <bst@pengutronix.de>

Fix warnings emitted by `tox -e lint`. Use recommendations from
black [1] for affected lines only.

[1] https://github.com/psf/black

Signed-off-by: Bastian Krause <bst@pengutronix.de>

Signed-off-by: Bastian Krause <bst@pengutronix.de>

Signed-off-by: Bastian Krause <bst@pengutronix.de>

While at it, drop the sample comment and name the workflow accordingly.
This gets displayed unter the "actions" tab as well as on the status
badge.

Signed-off-by: Bastian Krause <bst@pengutronix.de>

Drop the now unused Travis and LGTM badges. Add badges for GitHub
actions CI and documentation build tests.

Signed-off-by: Bastian Krause <bst@pengutronix.de>