Add command for opening Play Store.

lib/roles/app.js

@@ -622,6 +622,16 @@ module.exports = function(options) {
             )
           ])
         })
+        .on('store.open', function(channel, responseChannel) {
+          joinChannel(responseChannel)
+          push.send([
+            channel
+          , wireutil.transaction(
+              responseChannel
+            , new wire.StoreOpenMessage()
+            )
+          ])
+        })
     })
     .finally(function() {
       // Clean up all listeners and subscriptions