Add mongodb to package.json.
Add mongodb to package.json.

openshift/etherpad-example,vpistis/openshift-etherpad-lite,rameshlamba/markupspad,rameshlamba/teampad,rameshlamba/triospace,vpistis/openshift-etherpad-lite,rameshlamba/markupspad,openshift/etherpad-example,rameshlamba/triospace,openshift/etherpad-example,vpistis/openshift-etherpad-lite,rameshlamba/teampad