anchor.diff:  
   ENV yarnVersion 0.19.1
   
  -RUN mkdir -p /usr/src/app
  -WORKDIR /usr/src/app
   RUN mkdir -p yarn && cd yarn && \
     wget https://github.com/yarnpkg/yarn/releases/download/v$yarnVersion/yarn-v$yarnVersion.tar.gz && \
     tar xzf yarn-v$yarnVersion.tar.gz && rm yarn-v$yarnVersion.tar.gz && pwd && ls -l
  
positive.code: FROM node:6.2.2
  
  
  # It was set to info, which enables
  # log output for downloading dependencies.
  
negative.code: ENV NODE_ENV $NODE_ENV
  
  COPY package.json /usr/src/app/
  ## COPY yarn.lock /usr/src/app/
  
  # replacement for npm install
  RUN yarn/dist/bin/yarn --verbose
  COPY . /usr/src/app
  
  