I noticed the swh-environment jenkins job running the whole set of tests on the
dev version of swh modules was in bad shape since a while (see this log for instance).

So I took some time to fix it as it can be usefull to detect breaking changes
across swh modules.

The job was also missing a jenkins-job-builder definition file so the creation
of that diff.

The job will be aborted when one test suite fails to quickly detect flaky tests
and API breakage.

You can see in that log that swh module test suites are now correctly executed sequentially.