Make codecov project check informational and only fail on patch check #281

If a change overall removes lines and those lines were all covered, project coverage will be reduced.

This should not be a failure if patch coverage is good. Ideally we would allow project coverage to fail only if patch coverage is 100%, but I don't think that is possible.

This can be configured in codevcov.yaml: https://docs.codecov.com/docs/commit-status

Thoughts?