anchor.diff:  ######### 2. 安装sass                                  ####
   ######### 3. 安装compass                               ####
   ###########################################################
  -# apt-get git-core
   # && gem sources --remove https://rubygems.org/ \
   # && gem sources -a https://ruby.taobao.org/ \
   # && gem install sass \
  
positive.code: # eslint:   https://github.com/eslint/eslint
  # ghooks:   https://www.npmjs.com/package/ghooks
  RUN \
      npm install -g cnpm --registry=https://registry.npm.taobao.org \
      && npm install --global gulp \
      && npm install -g webpack \
  
negative.code:     && npm install intern \
      && npm install -g mocha \
      && npm install -g eslint \
      && npm install ghooks --save-dev \
      && apt-get purge -y --auto-remove git-core \
      && rm -rf /var/lib/apt/lists/*
  
  # Define working directory.
  WORKDIR /var/www
  