Removed old test.
Eager load children boards

Changed db.js and model.js in /boards to eager load children on all
retrival methods: find, boardByOldId, and all.
Updated board validation schema to accept children

Related to the previous commit, the board validation schema was edited
to allow an array of children objects. This array of children objects is
not saved to the DB and is generated only on retrivals.
fix bug where db was being created in the core directory

removed the __dirname from db.js