[BUGFIX beta] Publish ember-handlebars-compiler along with builds.

The compiler has been under some flux lately, and 1.2.0-beta.3's
compiler is not compatible with 1.1.2's.

This change will allow the `ember-handlebars-compiler` to be published
to the same `builds.emberjs.com` hierarchy as the rest of the assets.
Merge pull request #3776 from rjackson/publish_template_compiler

[BUGFIX beta] Publish ember-handlebars-compiler along with builds.