We are going to need to hide the report generation into the test runner
script, as we want the job to produce the reports even in case of
failure, instead of bailing out immediately.
We should have a single job for building both static and shared
versions of GTK. On the other hand, having a separate job for the
release build would be a plus.
Additionally, we shouldn't use an opaque script to build GTK; the only
step in the process that requires hand-holding is running the tests
suites under Xvfb, and having the build options visible from the YAML
file gives us a better idea of what kind of build we're running.
