Remove extra slash from assetPath.

`this.bowerDirectory` does not contain a trailing slash so we should
not add one back.
move qunit out of core and into an addon
[BUGFIX] Addons with empty directories
Merge pull request #1621 from bcardarella/bc-fix-addon-empty-dirs

[BUGFIX] Addons with empty directories
Enable `ember init` inside an addon.

* Add `Project.prototype.isEmberCLIAddon`.
* Use `addon` blueprint for projects with the `ember-addon` keyword.
Merge pull request #1624 from rwjblue/addon-init

Enable `ember init` inside an addon.
Fix start-app.js location from addon generator
Merge pull request #1626 from bcardarella/bc-addon-generation-start-app-location

Fix start-app.js location from addon generator
Remove usage of rewire.
Merge pull request #1627 from rwjblue/remove-rewire

Remove usage of rewire.
Remove duplicate analytics helper.

I added `MockLeek` in #1627, and only just realized that we already have
a `MockAnalytics` object (that is much better).
Merge pull request #1629 from rwjblue/remove-duplicate-helper

Remove duplicate analytics helper.
Allow Blueprint to determine if entity name is required.

Prior to this change an entity name was always required (which makes
sense for all of our bundled blueprints). In some cases you just want to
run a generator that does not need a name (for example you are just
initializing some required files for an addon).

This change still requires an entity name by default, but allows the
blueprint to override the `normalizeEntityName` and prevent the error.
Allow addons to use history-support middleware

The addon test dummmy app's environment file was not being found by
project.config(). This feels a little hackey but will allow the project
class for the addon to find the proper environment file to tell history
support what locationType is supported.
Merge pull request #1631 from rwjblue/allow-blueprint-to-determine-if-entityname-is-required

Allow Blueprint to determine if entity name is required.
Use SilentError instead of rejecting with no error.

* Update `ember generate`.
* Update `ember destroy`.
* Update `ember init`.
* Update `ember new`.
Merge pull request #1632 from bcardarella/bc-fix-addon-history-support

Allow addons to use history-support middleware
Merge pull request #1295 from jakecraige/qunit-addon

QUnit is now an ember-cli addon
Don't generate private packages for Addons
Add .travis.yml to app blueprint.