squash RUN in Dockerfile

Dockerfile

@@ -1,25 +1,24 @@
 FROM tutum/curl:trusty
 MAINTAINER Israel Gayoso [email protected] 
 
-RUN curl https://packagecloud.io/gpg.key | apt-key add -
-RUN apt-get update
-RUN apt-get install -y apt-transport-https supervisor openssl pwgen
-RUN echo "deb https://packagecloud.io/basho/riak/ubuntu/ trusty main" >> /etc/apt/sources.list.d/basho.list
-RUN echo "deb-src https://packagecloud.io/basho/riak/ubuntu/ trusty main" >> /etc/apt/sources.list.d/basho.list
-
-RUN apt-get update
-RUN apt-get install -y riak
+RUN curl https://packagecloud.io/gpg.key | apt-key add - && \
+    apt-get update && \
+    apt-get install -y apt-transport-https supervisor openssl pwgen && \
+    echo "deb https://packagecloud.io/basho/riak/ubuntu/ trusty main" >> /etc/apt/sources.list.d/basho.list && \
+    echo "deb-src https://packagecloud.io/basho/riak/ubuntu/ trusty main" >> /etc/apt/sources.list.d/basho.list && \
+    apt-get update && \
+    apt-get install -y riak && \
+    rm -rf /var/lib/apt/lists/* && \
+    sed -i -e s/listener.http.internal/listener.https.internal/g /etc/riak/riak.conf
 
 # Riak's config 
 ENV RIAK_NODE_NAME "127.0.0.1"
 ADD ./app.config /etc/riak/app.config
-RUN sed -i -e s/listener.http.internal/listener.https.internal/g /etc/riak/riak.conf
 
 # Copy init script to make configuration after first run and password set
 ADD ./run.sh /run.sh
 ADD ./set_riak_password.sh /set_riak_password.sh
 ADD ./create_certificate.sh /create_certificate.sh
-
 ADD supervisord-riak.conf /etc/supervisor/conf.d/supervisord-riak.conf
 
 # Expose protocol buffers and HTTPS