Rework the internals of pr status report to not depend on local repos
Rework the internals of pr status report to not depend on local repos

When running integration tests on GitLab, we don't have a local clone of
all the repos. Instead, we have env variables like <REPO>_REV_GIT_SHA
with the specific Git commit under test. Use this one for reporting
status in GitHub.

Changelog: None

Signed-off-by: Lluis Campos <9244cb41c39addfc5cf236920b776ea2820513d0@northern.tech>

mendersoftware/meta-mender-qemu