oeqa/core/runner: dump stdout and stderr of each test case
Some CI pipelines might perform further processing of the test output
(for instance, to plot some metrics into a chart). However, Since `thud`
we switched away from the XML-based jUnit reporting, and at the same
time we lost the ability of collecting the stdout and stderr of the
various tests.
We now restore this functionality by adding `stdout` and `stderr` keys
to the JSON reports. This behavior is off by default; in order to enable
it, one must set the `TESTREPORT_FULLLOGS` variable in the bitbake
configuration.
Signed-off-by: Alberto Mardegan <amardegan@luxoft.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
