Added router benchmarks

NullResponse_test.go

@@ -0,0 +1,11 @@
+package server_test
+
+import "net/http"
+
+// NullResponse implements the http.ResponseWriter interface with
+// empty methods to better understand memory usage in benchmarks.
+type NullResponse struct{}
+
+func (r *NullResponse) Header() http.Header       { return nil }
+func (r *NullResponse) Write([]byte) (int, error) { return 0, nil }
+func (r *NullResponse) WriteHeader(int)           {}