Renamed addon/ember-cpm.js to addon/index.js.

This allows to import all the ember-cpm namespace using
```js
import EmberCPM from "ember-cpm";
```
instead of
```js
import EmberCPM from "ember-cpm/ember-cpm";
```
Fix bug in macro bluprint: Test must import from dasherized file
Merge pull request #88 from cibernox/rename_ember-cpm_to_index

Rename ember cpm to index