Restart docker container itself instead of managing processes inside …

…the container (resolves cncjs#371)

Dockerfile

@@ -1,12 +1,10 @@
 FROM node:8
 MAINTAINER Cheton Wu <[email protected]>
 
-# cache package.json and node_modules to speed up builds
 ADD package.json package.json
 RUN npm i npm@latest -g
 RUN npm install --production
-RUN npm install -g nodemon
 
 ADD . .
 EXPOSE 8000
-CMD ["nodemon", "bin/cnc"]
+CMD ["bin/cnc"]