Refactoring the tests

Better use of promises and sharing of fixture data between tests...
Implemented and tested findQuery
No need to duplicate the primaryKey in the saved object. Lawnchair is insisting it's called key so we'll not also store it under primary key...
Cleaner use of promises to avoid rightward drift...
Linting...
Tests for Model.fetch
Splitting the tests out into modules ready to start testing relationships...