Does not work with ember data models with more than one attr

[luketheobscure]

Version

3.0.0-beta.9

Test Case

#406

Steps to reproduce

Attempts to work with a changeset for an ember data model with more than one attr fails when it tries to commit the changes.

It appears to be a bug somewhere inside buildPathToValue. Given a simple model like {foo: 1, bar: 2} it will attempt to set a value at foo.bar.

Expected Behavior

Saving models with more than one attr should not throw errors.

Actual Behavior

Models should save. ;)

[luketheobscure]

It looks like it boils down to unexpected behavior when checking foo.hasOwnProperty(key).

[luketheobscure]

I was able to fix it, but I'm not sure it's the ideal solution: 6170b40

Edit: Spoke to soon. Adding a relationship to that model will result in the same kind of bug.

[luketheobscure]

PR now has fixes for all the scenarios I found.

[luketheobscure]

Fixed by #406