Makefile: slightly better messaging

Hide commands and print out friendly success messages.
script/run exits with status 1 on errors

The build has been failing on some of the prerelease versions
for a while, but Travis was still reporting success because the
test command always exited successfully.
Fix TranslateableAttributes tests on Ember Canary

These tests included
```js
this.renderTemplate('{{view titleTranslation="foo.bar"}}');
```
which breaks on Ember Canary because the `{{view}}` helper no
longer assumes `Ember.View` by default, but instead asks the
container for `view:default`.

This commit changes `renderTemplate` to create an `Ember.Container`,
register an anonymous subclass of `Ember.View` as `view:toplevel`,
and set that container as the container for the created view.
Merge pull request #124 from jamesarosen/james/fix-canary

Fix Ember Canary Build