Fixes generator tests

- cascading test failures caused when no application.js file found during install generator. Because javascript convention changes between major rails versions, generating new sample app no longer reliably places a file at app/assets/javascripts/application.js. Now the install generator will touch that location if detect_js_format falls through, though there may be a better way to do this.

Author: aseroff

lib/generators/serviceworker/install_generator.rb

@@ -60,6 +60,8 @@ def detect_js_format
 
           return [ext, "//="]
         end
+        FileUtils.touch javascripts_dir("application.js")
+        ['.js', "//="]
       end
 
       def detect_layout

test/serviceworker/install_generator_test.rb

@@ -45,7 +45,7 @@ class ServiceWorker::InstallGeneratorTest < ::Rails::Generators::TestCase
     end
 
     assert_file "app/assets/javascripts/application.js" do |content|
-      assert_match(%r{\n//= require serviceworker-companion}, content)
+      assert_match(%r{//= require serviceworker-companion}, content)
     end
   end