Add getProperties

[duggiefresh]

Add getProperties since setProperties has already been added

[Turbo87]

@stefanpenner any plans to cut a release including this change?

[stefanpenner]

@Turbo87 thanks for the reminder

➜  ember-cli-shims git:(master) git tag v0.1.1
➜  ember-cli-shims git:(master) git push origin v0.1.1
Total 0 (delta 0), reused 0 (delta 0)
To git@github.com:ember-cli/ember-cli-shims.git
 * [new tag]         v0.1.1 -> v0.1.1