point SBFspot link at GitHub site (#86)
point SBFspot link at GitHub site (#86)

Because CodePlex has been in archive mode since 2017 and is supposed to
have been taken down in July this year already.

Co-authored-by: Giel van Schijndel <c6e1e670e6db0e77b72c3af92dfc03da91b5c6cc@tomtom.com>
kellerza/pysma