Added code coverage to tools/run_cpu_tests.sh

[gabrieldemarmiesse]

So the No module named _sqllite3 that we had before was an issue of python not being compiled with sqllite support. So nothing we can do about it in the custom-ops image.

Something we can do though is running it in the standard python3.5 docker image since the python used here supports it. So now, if we want to look at the code coverage in the master branch, we just need to look at the logs of the minimal cpu build.

Also the progress plain is used to have the full output when building the image locally. By default buildkit swallow the output. I tried and it also worked when DOCKER_BUILDKIT=0 so my hope is that this option won't break the script for people who don't have a version of docker recent enough.

See #1243 (comment)
and https://stackoverflow.com/questions/1210664/no-module-named-sqlite3

[seanpmorgan]

LGTM thanks very cool. 90% total coverage, but a few submodules are clearly lagging.