[DS-1008] AT Refactor: Clean up Admin Smoked

    - Convenience method to connect to SLI mongo db
    - Add clean up code for admin smoke test
    - Resolve LDAP server setup stepdef problem
    - Modify find users to get missing usernames
    - Require capybara
    - Capybarify admin smoke
    - Remove duplicate scenarios for yearly attendance
    - Add verification of student attendance events to attendance CRUD
    - Ensure bell schedule resource only contains expected links
    - Ensure that entity links only contain expected data