Use identifiers instead of literals when possible when adding new keys.

Fixes #7.

Merge pull request #12 from srvance/support-addons

Support addons

Advance the version number.

Bump the version.

Reformat the code to match the editorconfig.

Update package version.

Forgot to add the addon entry point to the package files.

Add the ember-addon keyword back in and the entry point to make it work

Remove `ember-addon` keyword. It breaks `ember g`.

Rev the revision for a new release.