The backend code for the todo manager demo.
    * definition.json - contains the tiles definition.  This will be added to the extension.zip when starting up.
    * backend/services.js contains the code to kick off updating tiles.
    * backend/routes/todos.js - Contains a simple REST todo manager.
    * backend/routes/configure/get.js - contains the configuration UI for the tile.
    * public/ -- contains all assets exposed from /todo