anchor.diff:      && npm install -g "npm@${NPM_VERSION}" \
       && npm cache clear
   
  -ENV REDIS_VERSION 3.0.7
  -ENV REDIS_DOWNLOAD_URL http://download.redis.io/releases/redis-3.0.7.tar.gz
  -ENV REDIS_DOWNLOAD_SHA1 e56b4b7e033ae8dbf311f9191cf6fdf3ae974d1c
  +ENV REDIS_VERSION 3.2.2
  +ENV REDIS_DOWNLOAD_URL http://download.redis.io/releases/redis-3.2.2.tar.gz
  +ENV REDIS_DOWNLOAD_SHA1 3141be9757532139f445bd5f6f4fae293bc33d27
   
   RUN set -x \
       && mkdir -p /usr/src/redis \
  
positive.code:     && make -C /usr/src/redis install \
      && rm -r /usr/src/redis
  
  ENV DOCKER_VERSION 1.10.3
  ENV DOCKER_SHA256 d0df512afa109006a450f41873634951e19ddabf8c7bd419caeb5a526032d86d
  
  RUN curl -fSL "https://get.docker.com/builds/Linux/x86_64/docker-$DOCKER_VERSION" -o /usr/local/bin/docker \
      && echo "${DOCKER_SHA256}  /usr/local/bin/docker" | sha256sum -c - \
      && chmod +x /usr/local/bin/docker
  
  ENV DOCKER_HOST tcp://docker:2375
  
  
negative.code: FROM python:2.7.12
  
  # add our user and group first to make sure their IDs get assigned consistently
  RUN groupadd -r freight && useradd -r -m -g freight freight
  