[DS-1008] Refactor bell schedules CRUD acceptance tests

    - Correct count of expected bell schedules for auto_crud tests
    - Refactoring of bell schedule ATs
    - Generalize steps for handling custom data
[DS-1008] Encapsulate AT DB Connection and clean up

    - Factor out Mongo connection into its own class
    - Refactored ugly multiple if statements into hash
    - Remove unneeded JSON parsing
[DS-1008] Simplify Odin data generation acceptance tests
[DS-1008] Improve Section CRUD AT
[DS-1008] Reinstate feature required for use by other ATs
[DS-1008] Fix count of bell schedules in AT
[DS-1008] Fix odin tests by generating 10students_optional scenario
Merge branch 'master' into DS-1013