1. Add missing ptest dependency (pytest-subtest)
2. The testsuite is installed in both the site-packages and ${PTEST_PATH}
folders, however some dependencies are only available in the site-packages
folder, so many test cases fail.
At this point of the branch lifecycle I decided not to refactor the recipe, but
rather to just use the installation in the site-packages dir to run the
tests (switch to that folder in the run-ptest script)
3. Fix the run-ptest script to output PASS/FAIL status.
Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
