ducky/subscriptions: 61583c1d3886 memstore.go

Create a listener that will create subscriptions. We need a listener (as discussed in c4cfceb2f2fb) that will create a Subscription whenever an auth.Profile is created. This is the beginning of that effort. It hasn't been tested, and all the pieces aren't in place, but it's a rough skeleton. We have a Dockerfile that will correctly build a minimal container for the listener. We have a build-docker.sh script that will correctly build a binary that will be used in the Dockerfile. We have a ca-certificates.crt, which are pulled from Ubuntu, and are necessary before we can safely consume SSL endpoints. We created a small consumer script that listens for events off NSQ, and calls the appropriate endpoint for our Subscriptions API. This is untested, and it doesn't build at the moment, but that's awaiting changes in the code.secondbit.org/auth.hg package. Finally, we have a wrapper.sh file that will expose the Stripe secret key being used from a Kubernetes secret file as an environment variable, instead.