message: Speed up Micro CI builds by switching to a prebuilt image
diff: -FROM ubuntu:16.04
  +# Use a prebuilt Python image instead of base Ubuntu to speed up the build process,
  +# since it has all the build dependencies we need for Micro and downloads much faster
  +# than the install process.
  +FROM python:3.5-stretch
  LABEL maintainer="Pete Warden <petewarden@google.com>"
  -
  -# We only need a few dependencies for Micro builds, so reduce the latency by skipping
  -# most of the packages used by other CI images.
  -RUN apt-get update && apt-get install -y sudo make curl build-essential zip tar python
  