Remove 'ember-cli/' path from ember-cli-test-loader in blueprint

[ballPointPenguin]

Fixes issue with using the generator with ember-cli 1.13.5 and up.

$ ember -v
version: 1.13.6
node: 2.4.0
npm: 2.13.2
os: linux x64
$ ember new jamocha-shake
...
$ cd jamocha-shake
$ ember generate ember-cli-qunit
version: 1.13.6
installing ember-cli-qunit
Installing browser packages via Bower...
cached git://github.com/dockyard/ember-qunit-notifications.git#0.0.7
cached git://github.com/jquery/qunit.git#1.17.1
cached git://github.com/rwjblue/ember-qunit-builds.git#0.4.6

Package ember-cli/ember-cli-test-loader=ember-cli/ember-cli-test-loader not found
Error: Package ember-cli/ember-cli-test-loader=ember-cli/ember-cli-test-loader not found

This might be related to strictness introduced by ember-cli/ember-cli#4430

[rwjblue]

http://bower.io/search/?q=ember-cli-test-loader suggests that ember-cli-test-loader is not listed in the bower registry, so I am not sure how this change would work...

[ballPointPenguin]

Good point, @rwjblue . Maybe it worked only by finding it in my local bower cache. I'll keep trying...

[ballPointPenguin]

Accomplished by #73