Remove Ember Tests from Rails Engine

Remove support for viewing Ember tests through Rails.

Instead, use `ember test` or `ember test --serve` from within the Ember
directory.

CHANGELOG.md

@@ -1,6 +1,8 @@
 master
 ------
 
+* Remove support for viewing Ember tests through Rails. Instead, use `ember
+  test` or `ember test --serve` from within the Ember directory.
 * Remove `build_timeout` configuration [#259]
 * Disable JS minification when generating Heroku setup [#238]
 * `BuildError#message` includes first line of backtrace. [#256]

README.md

@@ -230,26 +230,6 @@ export default DS.RESTAdapter.extend({
 });
 ```
 
-## Ember Test Suite
-
-To run an Ember app's tests in a browser, mount the `EmberCli::Engine`:
-
-```ruby
-# config/routes.rb
-
-Rails.application.routes.draw do
-  mount EmberCli::Engine => "ember-tests" if Rails.env.development?
-
-  root "application#index"
-end
-```
-
-Ember tests are served based on the route you mount the Engine on (in this
-example, `/ember-tests`) and the name of the Ember app.
-
-For example, to view tests of the `frontend` app, visit
-`http://localhost:3000/ember-tests/frontend`.
-
 ### Integrating with Rake
 
 EmberCLI Rails exposes the `ember:test` Rake task to execute Ember's test suite.

lib/ember-cli/path_set.rb

@@ -53,10 +53,6 @@ def initialize(app:, rails_root:, ember_cli_root:, environment:, configuration:)
       root.join("Gemfile")
     end
 
-    define_path :tests do
-      dist.join("tests")
-    end
-
     define_path :node_modules do
       root.join("node_modules")
     end

spec/lib/ember-cli/path_set_spec.rb

@@ -80,14 +80,6 @@
     end
   end
 
-  describe "#tests" do
-    it "is a child of #dist" do
-      path_set = build_path_set
-
-      expect(path_set.tests).to eq path_set.dist.join("tests")
-    end
-  end
-
   describe "#node_modules" do
     it "is a child of #root" do
       path_set = build_path_set