Add backbone tests
Fix syntax, stub missing things
Get backbone tests running
BBTest: ‘initialize with defaults’ - fix test for ampersand semantics.
BBTest - fix broken ported tests
BBTest - “underscore methods” - skip for now.
BBTest - Add proxyquire to dev-deps.
BBTest - constructor being improperly set on models.
BBTest - “chain” - skip for now.
BBTest - “nested set triggers with correct options” - skip for now.

Not entirely sure what this is trying to test.
BBTest - “using a non-default id attribute” - skip for now.

Not sure how this should be handled in ampersand-model, if at all.
BBTest - “clear” - skip for now.

Clear in backbone triggers only a single change event, since we are looping over properties, we trigger lots.
BBTest - “defaults” - partially fix and skip for now.

Backbone obviously defines defaults differently, so fixed that. However test still fails, because the test tries to set a property as “undefined” which raises an exception as it doesn’t match the type. This happens _even_ if the type is set to “any”.
BBTest - skip sync tests for now.
BBTest - "set value regardless of equality/change” - I’m not sure how this one passes in backbone even.
BBTest - “#871, set with attributes property” - skip for now

Not sure how to handle this.
BBTest - fix couple of tests for tape.
BBTest - “set: undefined values” - skip for now.

Unsure how this should really be handled in &?
BBTest - skip some more save tests.
BBTest - fix test for tape.