Add old database number
Merge branch 'master' of https://github.com/OpenDSA/OpenDSA-server
Check on the variables defined by the student
Unit test modified for stack sorting exercise
initialized old database data to 0
Displayed student score in percentage and added maximum number of points
in class activity page.
Fixed bug in widget data function
Bad idea to create a new account when logging interactions.
Merge branch 'master' of https://github.com/OpenDSA/OpenDSA-server
Merge branch 'master' of https://github.com/OpenDSA/OpenDSA-server
removed old courses dates.