Changed so properties can be read from ember-data records

In ember-data records are accessed via the get method.
If d[property] doesn't exist then d.get(property) will be called.
Reference: Issue #34
Added check for get method on d in reference to ISsue #34

Check if get is defined on d before you attempt to invoke it. Otherwise
we'll run into the issues we're seeing in Travis.
In ember-data records are accessed via the get method.
If d[property] doesn't exist then d.get(property) will be called.
Reference: Issue #34
Merge pull request #35 from bentacles/master

Changed so properties can be read from ember-data records