Make php 7.0 cs fixer

code-formatter/Dockerfile

@@ -1,4 +1,4 @@
-FROM node:8-slim
+FROM node:8-stretch
 
 # https support
 RUN apt-get update && \
@@ -8,7 +8,7 @@ RUN apt-get update && \
 RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add - && \
   echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list && \
   apt-get update && \
-  apt-get install -y yarn php5-cli && \
+  apt-get install -y yarn php7.0-cli && \
   apt-get clean && \
   rm -rf /var/lib/apt/lists/* /etc/apt/sources.list.d/* /tmp/* /var/tmp/*