Signed-off-by: David Runge <dvzrv@archlinux.org>

Use upstream source tarball.
Switch to correct SPDX license identifier for project.
Ensure pbr can set the version when creating the wheel.

Add all direct dependencies.

Move python-pbr to makedepends and add python-click and python-docutils to depends.

Switch to PEP517.

Simplify quoting in file.
Remove unneeded prepare().