fix docker

nodejs/Dockerfile

@@ -1,5 +1,8 @@
 FROM node:4.4-onbuild
 EXPOSE 1207
+RUN apt-get install python-software-properties
+RUN add-apt-repository ppa:rwky/redis
+RUN apt-get update
 RUN apt-get install redis-server
 RUN redis-server
 RUN npm install -g forever