Enable AWS App Mesh

[timothy-spencer]

This gets AWS app mesh going, ala #8.

It also tweaks the 2048 app fixture to use app mesh. The loadbalancer currently does not work for some reason, but you can do kubectl port-forward service/gw-2048 8443:443 and then go to https://localhost:8443 to see it work. Then, to know that ssl is going, you can look at:

kubectl  exec -it deployment.apps/deployment-2048 -c envoy -- curl -s localhost:9901/stats | grep -e "ssl.handshake"
kubectl  exec -it deployment.apps/gw-2048 -c envoy -- curl -s localhost:9901/stats | grep -e "ssl.handshake"

to see that there are ssl handshakes happening between the gw and the deployment.