health: Adding upload feature

When using health mode with edeploy, it's useless being able to report
data to the server.

upload-health.py is a fork of upload.py but only keep the saving part of
it. No script is returned to the client.

A specific health/ directory got created to save the uploaded files.
health-check: No global test if only 1 disk

When performing the storage test, if a single disk is detected there is
no need to do make a isolated and simultaenous test as it means doing
the same test twice.

So let's ignore the simultaneous test if a single disk got detected