Refactoreds for async fs operations, added json parse error handling
Fixed validateFunction, added OPTIONAL argument type, refactored validateObject to throw errors non-object types (number, string, etc.)
Added noop for optional callback default values and added validation for loading/saving to *.json filepaths only.
Refactored tests for new FlatFileAccess async format
Updated for current definition of validateObject
Merge pull request #26 from UofM-COMP4350-4/fileaccess-jasonrobitaille

Refactoreds for async fs operations, added json parse error handling