util-gem5art: Add gem5art packages

gem5art is a utility to help manage the artifacts used in gem5
experiments, the output from those experiments, and running the
experiments in parallel (artifacts, run, and tasks packages

The current documentation can be found on readthedocs [1], but we are
planning on migrating this to the gem5 website very soon [2].

More information on the motivation and design was discussed at the gem5
workshop last summer. See the blog post [3] for more details.

The current version (v1.3.1) is already deployed on PyPI, and you can
install it with `pip install gem5art-artifact gem5art-run gem5art-tasks`

Once this is merged, we will update the PyPI version to match the
version in gem5 (v1.4.0). The only differences are mostly documentation
based (pointers to the documentation and source), but we have also
updated the style to strictly match PEP8 with black [4].

gem5art is a *utility* to use with gem5. So, we expect that the
versioning and release schedule will not necessarily match gem5's (hence
a separate versioning structure and separate RELEASE-NOTES, etc.).

[1]: https://gem5art.readthedocs.io/en/latest/
[2]: https://www.gem5.org/documentation/gem5art
[3]: http://www.gem5.org/2020/05/26/gem5art.html
[4]: https://github.com/psf/black

Change-Id: Ic8af63edf0cb7df4693a46413f7278a3e8ac6846
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/42121
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Ayaz Akram <yazakram@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
28 files changed