(maint) Update container user for builds

Prior to this commit, the docker image would fail to build as the
upstream grafana container sets a non root user. This commit changes the
user to root for the package installation and then back to the non root
user.

Author: Jarret Lavallee

grafana-puppetserver/Dockerfile

@@ -1,6 +1,8 @@
 FROM grafana/grafana
 MAINTAINER Reid Vandewiele <reid@puppet.com>
 
+USER root
+
 COPY build/* /grafana-puppet/
 RUN apt-get update && \
     apt-get -y install curl && \
@@ -9,6 +11,8 @@ RUN apt-get update && \
     rm -rf /var/lib/apt/lists/* && \
     rm -rf /tmp/*
 
+USER grafana
+
 ENTRYPOINT /grafana-puppet/run.sh
 
 LABEL org.label-schema.vendor="Reid Vandewiele" \