Introduce lib/ember_cli.rb

So that the files and tests follow Ruby's naming idioms, move the
contents of `lib/ember-cli-rails.rb` to `lib/ember_cli.rb`, to match the
constant that the file contains.

lib/ember-cli-rails.rb

@@ -1,69 +1,3 @@
-require "fileutils"
-require "ember-cli-rails-assets"
-require "ember_cli/engine"
-require "ember_cli/configuration"
-require "ember_cli/helpers"
-require "ember_cli/errors"
-
-module EmberCli
-  extend self
-
-  def configure
-    yield configuration
-  end
-
-  def configuration
-    Configuration.instance
-  end
-
-  def app(name)
-    apps.fetch(name) do
-      fail KeyError, "#{name.inspect} app is not defined"
-    end
-  end
-
-  def build(name)
-    app(name).build
-  end
-
-  alias_method :[], :app
-
-  def skip?
-    ENV["SKIP_EMBER"].present?
-  end
-
-  def install_dependencies!
-    each_app(&:install_dependencies)
-  end
-
-  def test!
-    each_app(&:test)
-  end
-
-  def compile!
-    cleanup!
-    each_app(&:compile)
-  end
-
-  def root
-    @root ||= Rails.root.join("tmp", "ember-cli").tap(&:mkpath)
-  end
-
-  def env
-    @env ||= Helpers.current_environment
-  end
-
-  delegate :apps, to: :configuration
-
-  private
-
-  def cleanup!
-    root.children.each { |tmp_file| FileUtils.rm_rf(tmp_file) }
-  end
-
-  def each_app
-    apps.each { |_, app| yield app }
-  end
-end
+require "ember_cli"
 
 EmberCLI = EmberCli

lib/ember_cli.rb

@@ -0,0 +1,67 @@
+require "fileutils"
+require "ember-cli-rails-assets"
+require "ember_cli/engine"
+require "ember_cli/configuration"
+require "ember_cli/helpers"
+require "ember_cli/errors"
+
+module EmberCli
+  extend self
+
+  def configure
+    yield configuration
+  end
+
+  def configuration
+    Configuration.instance
+  end
+
+  def app(name)
+    apps.fetch(name) do
+      fail KeyError, "#{name.inspect} app is not defined"
+    end
+  end
+
+  def build(name)
+    app(name).build
+  end
+
+  alias_method :[], :app
+
+  def skip?
+    ENV["SKIP_EMBER"].present?
+  end
+
+  def install_dependencies!
+    each_app(&:install_dependencies)
+  end
+
+  def test!
+    each_app(&:test)
+  end
+
+  def compile!
+    cleanup!
+    each_app(&:compile)
+  end
+
+  def root
+    @root ||= Rails.root.join("tmp", "ember-cli").tap(&:mkpath)
+  end
+
+  def env
+    @env ||= Helpers.current_environment
+  end
+
+  delegate :apps, to: :configuration
+
+  private
+
+  def cleanup!
+    root.children.each { |tmp_file| FileUtils.rm_rf(tmp_file) }
+  end
+
+  def each_app
+    apps.each { |_, app| yield app }
+  end
+end