isoping: build with Docker

This will let us deploy a minimal image with isoping to GKE. After
some research I've been able to get the container size down to 6 MiB.

I've pushed this to a manually configured GKE cluster and confirmed
that it works, too.

Also include Kubernetes configs for a small cluster running on GKE.

Change-Id: Ib061e3c8a85126009f8c40b4e93e3e7f2d18aae1
6 files changed