Update README.md
updates for ember-data beta.10, `RelationshipChange` was removed
Merge pull request #32 from ethanresnick/patch-1

Update README.md
Merge pull request #35 from plyfe/ember-data-1.0.0-beta.10-updates

updates for ember-data beta.10, `RelationshipChange` was removed
Builds 0.1.0