Bump calibration version number
Fixes #71 (closed) and allows the user to optionally specify the calibration version number.
This adds a few tests to test both version 8 and 9 of the calibration. I would suggest that this be the approach moving forward, i.e. we add a new set of tests for each new version of the calibration but keep the old ones. We still want to make sure applying the old values gives the exepected (albeit outdated) results.