anchor.diff:  
   ### Stage 5 - Base image for builds to share args and environment variables
   FROM base as build-base
  +RUN apk --no-cache update \
  +  && apk --no-cache upgrade \
  +  && apk add --no-cache git
   # ARGs
   ARG API_HOST
   ARG DISCOVERY_HOST=hakken:8000
  
positive.code:   PUBLISH_HOST=$PUBLISH_HOST \
    SERVICE_NAME=$SERVICE_NAME \
    ROLLBAR_POST_SERVER_TOKEN=$ROLLBAR_POST_SERVER_TOKEN \
    NODE_ENV=production
  
  
  
negative.code: ARG PUBLISH_HOST=hakken
  ARG SERVICE_NAME=blip
  ARG ROLLBAR_POST_SERVER_TOKEN
  ARG TRAVIS_COMMIT
  # Set ENV from ARGs
  ENV \
    API_HOST=$API_HOST \
  