Bump to version 1.93 in preparation for release
Bump to version 1.93 in preparation for release

Signed-off-by: Marcus D. Hanwell <cf7042e2e8eee958b5bcde1ae2cbefef82efc184@kitware.com>

ghutchis/avogadroapp,ghutchis/avogadroapp,OpenChemistry/avogadroapp,ghutchis/avogadroapp,ghutchis/avogadroapp,OpenChemistry/avogadroapp,OpenChemistry/avogadroapp,OpenChemistry/avogadroapp