More RuboCop cleanup not directly related to the PR

lib/kitchen/driver/gce.rb

@@ -200,7 +200,7 @@ def authorization
       end
 
       def winrm_transport?
-        instance.transport.name.downcase == "winrm"
+        instance.transport.name.casecmp("winrm").zero?
       end
 
       def update_windows_password(server_name)
@@ -416,7 +416,7 @@ def image_alias_url
 
         latest_image = connection.list_images(image_project).items
           .select { |image| image.name.start_with?(image_prefix) }
-          .sort { |a, b| a.name <=> b.name }
+          .sort_by(&:name)
           .last
 
         return if latest_image.nil?

spec/kitchen/driver/gce_spec.rb

@@ -381,7 +381,7 @@
     end
 
     it "raises an exception if the block raises something other than a ClientError" do
-      expect { driver.check_api_call { raise RuntimeError.new("whoops") } }.to raise_error(RuntimeError)
+      expect { driver.check_api_call { raise "whoops" } }.to raise_error(RuntimeError)
     end
 
     it "returns true if the block does not raise an exception" do
@@ -832,7 +832,7 @@
 
     it "accepts custom metadata" do
       foo = double("foo")
-      config[:metadata] = { 'foo' => 'bar' }
+      config[:metadata] = { "foo" => "bar" }
 
       expect(instance).to receive(:name).and_return("instance_name")
       expect(driver).to receive(:env_user).and_return("env_user")