Add a gratuitous outline to flights-app.

This is so we have minimal coverage of outline painting.

R=esprehn@chromium.org

Review URL: https://codereview.chromium.org/878803002

examples/flights-app/flights-app.sky

@@ -46,6 +46,7 @@
 
     .route-result {
       margin: 16px 16px 0 16px;
+      outline: 1px solid black;
     }
 
     .route-title {