[DS-965] Get Odin tests working

    - Fix discipline incident spec
    - Fix and clean pre-requisite builder spec
    - Fix and clean world builder spec
    - Clean and fix Odin integration spec
    - Update baseline XML files
    - Update baseline for InterchangeEducationOrgCalendar.xml (plus refactoring to idiomatic ruby)
    - Update baseline expected XML
    - Interim commit
    - Minor improvements to spec
    - Fix specs since Session requires passing calendar_dates on new
    - Attendance generator spec no longer expects AttendanceEventType
#DS-912
Merge branch 'master' into ds-912
#DS-912
ATs added