rest_adapter: Remove unused `set` definition
Merge pull request #2033 from duggiefresh/rest_adapter

rest_adapter: Remove unused `set` definition
Stop using deprecated methods

Replace to use some methods that Ember.js recommends.
* `findProperty` -> `findBy`
* `mapProperty` -> `mapBy`
* `filterProperty` -> `filterBy`
* `everyProperty` -> `isEvery`
Merge pull request #2034 from tricknotes/stop-using-deprecated-methods

Stop using deprecated methods
Update readme, add link to local travis
Add normalizePayload call to embedded-records' extractArray and extractSingle