Use new hash syntax for generators gem method

The Gemfile of new application uses ruby 1.9 hashes. Gem method of
generators should use them too. It prevents from mixing two kinds of
syntax in one file.

railties/lib/rails/generators/actions.rb

@@ -27,7 +27,7 @@ def gem(*args)
         log :gemfile, message
 
         options.each do |option, value|
-          parts << ":#{option} => #{value.inspect}"
+          parts << "#{option}: #{value.inspect}"
         end
 
         in_root do

railties/lib/rails/generators/rails/plugin_new/plugin_new_generator.rb

@@ -139,7 +139,7 @@ def gemfile_entry
 
       gemfile_in_app_path = File.join(rails_app_path, "Gemfile")
       if File.exist? gemfile_in_app_path
-        entry = "gem '#{name}', :path => '#{relative_path}'"
+        entry = "gem '#{name}', path: '#{relative_path}'"
         append_file gemfile_in_app_path, entry
       end
     end

railties/test/generators/actions_test.rb

@@ -67,6 +67,14 @@ def test_gem_should_insert_on_separate_lines
     assert_file 'Gemfile', /^gem "rspec-rails"$/
   end
 
+  def test_gem_should_include_options
+    run_generator
+
+    action :gem, 'rspec', github: 'dchelimsky/rspec', tag: '1.2.9.rc1'
+
+    assert_file 'Gemfile', /gem "rspec", github: "dchelimsky\/rspec", tag: "1\.2\.9\.rc1"/
+  end
+
   def test_gem_group_should_wrap_gems_in_a_group
     run_generator
 

railties/test/generators/plugin_new_generator_test.rb

@@ -279,7 +279,7 @@ def test_creating_plugin_in_app_directory_adds_gemfile_entry
 
     run_generator [destination_root]
 
-    assert_file gemfile_path, /gem 'bukkits', :path => 'tmp\/bukkits'/
+    assert_file gemfile_path, /gem 'bukkits', path: 'tmp\/bukkits'/
   ensure
     Object.send(:remove_const, 'APP_PATH')
     FileUtils.rm gemfile_path
@@ -294,7 +294,7 @@ def test_skipping_gemfile_entry
     run_generator [destination_root, "--skip-gemfile-entry"]
 
     assert_file gemfile_path do |contents|
-      assert_no_match(/gem 'bukkits', :path => 'tmp\/bukkits'/, contents)
+      assert_no_match(/gem 'bukkits', path: 'tmp\/bukkits'/, contents)
     end
   ensure
     Object.send(:remove_const, 'APP_PATH')