Allow 'chemical json' for cjson version key
Allow 'chemical json' for cjson version key

'chemical json' was used for cjson version 0. Allow
this key to be used.

Signed-off-by: Patrick Avery <743342299f279e7a8c3ff5eb40671fce3e95f13a@kitware.com>

OpenChemistry/mongochemserver