CLONE - An administrator can create a cohort and add users to it

1. Login as an administrator, go to Settings > Site administration > Users > Accounts > Cohorts and create a cohort.
2. Click the add users icon in the edit column and select some users then add them to the cohort.
3. Click the 'Back to cohorts' button and check that the cohort is listed with the correct cohort size.
4. Go to Settings > Site administration > Users > Accounts > Bulk user actions and select some users and add them to the selected list.
5. Add the selected users to a cohort.
6. Go to Settings > Site administration > Users > Accounts > Cohorts and check that the cohort is listed with the correct cohort size.