modified dockerfile

Dockerfile

@@ -9,7 +9,6 @@ FROM ubuntu
 # MAINTAINER name Chunteng Xiao
 RUN apt-get update
 RUN apt-get install -y nodejs nginx npm
-RUN rm -v /etc/nginx/nginx.conf
 RUN npm install -g cnpm --registry=https://registry.npm.taobao.org
 ADD default /etc/nginx/sites-available
 EXPOSE 80