Clean up the klarlack container a bit after installation.

container/Dockerfile.klarlack

@@ -34,6 +34,13 @@ RUN apt-get install -y varnish=${VERSION} \
     varnish-modules \
     varnish-objvar
 
+RUN apt-get remove -y -q curl gnupg && \
+    apt-get autoremove -y -q && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/* && \
+    rm -rf /usr/share/doc && \
+    rm -rf /usr/share/man
+
 # Set the varnish GID to 998 as in the packagecloud install.
 RUN /bin/mkdir /run/varnish && \
     /usr/sbin/groupmod -g 998 varnish