add route to test chunked encoding

app.rb

@@ -427,11 +427,14 @@ route :delete, :get, :patch, :post, :put, "/status/:code" do
 end
 
 get "/chunked/:delay" do
+  content_type "application/x-ndjson"
+
   delay = Float(params[:delay])
   stream do |out|
-    out << "Hello, world!\n"
+    30.times do |i|
+      out << jsonify({id: i, message: i % 2 == 0 ? "tick" : "tock"})
       sleep delay
-    out << "Hello, world!\n"
+    end
   end
 end