Make Dockerfile spec compliant

Author: mrb

Dockerfile

@@ -1,9 +1,15 @@
 FROM node
 
-WORKDIR /usr/src/app
+MAINTAINER Michael R. Bernstein
+
+RUN useradd -u 9000 -r -s /bin/false app 
 
 RUN npm install glob
 
+WORKDIR /code
 COPY . /usr/src/app
 
+USER app
+VOLUME /code
+
 CMD ["/usr/src/app/bin/fixme"]