sphinx as hard dependency (is it really necessary?)
@marcin reported that Stork fails to build if sphinx is not present. Original report here: #426 (comment 169328)
One (easier) way to semi-address this would be to update the docs and say that sphinx and sphinx-rtd-theme is now mandatory.
A better way would be to check if sphinx is available and don't generate docs and man pages if it isn't. This would make the user experience better.