follow best practices

Author: BertrandGouny

image/Dockerfile

@@ -5,16 +5,16 @@ MAINTAINER Bertrand Gouny <bertrand.gouny@osixia.net>
 # https://github.com/osixia/docker-light-baseimage/blob/stable/image/tool/install-service-available
 RUN echo "deb http://http.debian.net/debian experimental main" >> /etc/apt/sources.list && apt-get -y update \
 	  && LC_ALL=C DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
-	     -t experimental tinc
+	     -t experimental tinc  \
+		&& apt-get clean \
+		&& rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
 # Add service directory to /container/service
 ADD service /container/service
 
-# Use baseimage install-service script and clean all
+# Use baseimage install-service script
 # https://github.com/osixia/docker-light-baseimage/blob/stable/image/tool/install-service
-RUN /container/tool/install-service \
-    && apt-get clean \
-    && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+RUN /container/tool/install-service
 
 # Add default env variables
 ADD environment /container/environment/99-default