* Improves stability of reported coverage and makes it nicer
With this change we only upload coverage report in the case
when all tests were successuful and actually executed. This means
that coverage report will not be run when the job gets canceled.
Currently a lof of coverage reports gathered contain far less
coverage because when static check fails or docs some test jobs
could already submit their coverage - resulting in partial coverage
reports.
With this change we also remove comment from coverage report
and replace it with (for now) informational status message published
to github. If we see that it works, we can change it to a
PR-failing status if coverage drops for a given PR.
This way we might get our coverage monotonously increasing :).
Kaxil Naik
Kamil Breguła
Jarek Potiuk