Stamp commit sha in outputs

[alasdairwilson]

Had to hack this a bit,

I have had this exact same issue before on other projects: the .git file is not in the docker container by design which means we can't resolve the SHA.

So we have to pass through in terms of env var when using docker but can use git itself via subprocess when being rean via python -m

closes #44

[codecov]

Codecov Report

❌ Patch coverage is 79.16667% with 5 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
vertex/io.py	78.26%	5 Missing ⚠️

Files with missing lines	Coverage Δ
vertex/IsaricDraw.py	12.54% <100.00%> (+0.17%)	⬆️
vertex/io.py	71.00% <78.26%> (+0.39%)	⬆️

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[sr-murthy]

@alasdairwilson Approved, with a couple of comments.