Merge branch 'hotfix/1.3-hf2'
CNS-732: Modify Course Enrollment for STU

Update invitation email template, and add link for STU cad server on
the login page
Bumped version string to 1.3-hf3 for Sandbox build.
Merge branch 'hotfix/1.3-hf3' into develop
Merge remote-tracking branch 'origin/develop' into develop