Some testing fixes.

Added a online category to some tests which require online access.
Saved a copy of CKAN-meta-testkan.zip so that the sanity checker tests are offline.
Fixed KSP.Training test to work on windows as well as linux.
Actually looking again I may be correct in this case. 
To return null
available_modules[module].Latest(ksp_version)
must return null.
For this to occur the AvailableModule in available_modules[module] must have a empty module_version or a module_version with nulls in it. Neither of which is currently the case.
However this could change so I will revert it back.