Before when a subtest failed, the text of the failed assertion was not
printed. This changes makes sure that it is printed in both the console
and the aggregated test output.
Also fix a couple typing errors.
This change moves all of Servo's WPT Python support scripts into one
directory as they were previously scattered throughout the directory
structure. This should allow more code reuse and make it easier to
understand how everything fits together.
The changes:
- `tests/wpt/update` → `python/wpt/importer`
- `etc/ci/upstream-wpt-changes/wptupstreamer` → `python/wpt/exporter`
- `etc/ci/upstream-wpt-changes/test.py` → `python/wpt/test.py`
- `etc/ci/upstream-wpt-changes/tests` → `python/wpt/tests`
- `tests/wpt/servowpt.py` →
- `python/wpt/update.py`
- `python/wpt/run.py`
- `tests/wpt/manifestupdate.py` → `python/wpt/manifestupdate.py`
This change also removes
- The ability to run the `update-wpt` and `test-wpt` commands without
using `mach`. These didn't work very well, because it was difficult
to get all of the wptrunner and mach dependencies installed outside
of the Python virtualenv. It's simpler if they are always run through
`mach`.
- The old WPT change upstreaming script that was no longer used.
