Patchwork: fix heading level, expand description
For implementation details, see <code>.travis.yml</code>, <code>scripts/travis/</code> and <code>scripts/build/</code> in CRIU sources for details.
== Patchwork ==
[https://patchwork.criu.org/project/criu Patchwork] is a web patch tracking system for projects using a mailing list for contributions and reviews.
In CRIU it is used to
execute tests for each patch series.
=== Non-x86 architectures ===