Trying to improve image build time

Dockerfile

@@ -23,30 +23,28 @@ RUN useradd eos-user
 
 # Docker will aggressively cache the following command, but this is fine, since
 # these packages are not updated often.
-RUN yum clean all; \
-    yum -y --nogpg update; \
-    yum -y --nogpg install \
+RUN yum -y --nogpg install \
     heimdal-server heimdal-workstation \
     krb5-workstation yum-plugin-priorities \
     createrepo initscripts less emacs vim nano \
-    davix git parallel compat-libf2c-34 libgfortran \
+    git parallel compat-libf2c-34 libgfortran \
     gdb gcc-c++ cmake3 libacl-devel perl-Test-Harness \
     rpm-build bzip2 automake autoconf libtool
 
+# Special packages, must be installed un-cached.
+RUN yum clean all; \
+    yum -y --nogpg install \
+    quarkdb grid-hammer davix
+    
 # Install new EOS from created repo - the ADD command will reset the docker cache,
 # and any commands after that point will be uncached.
 ENV EOSREPODIR="/repo/eos"
 ADD cc7_artifacts ${EOSREPODIR}
 
-# Special packages, must be installed un-cached.
-RUN yum clean all; \
-    yum -y --nogpg install \
-    quarkdb grid-hammer grid-hammer-debuginfo
-
 RUN createrepo ${EOSREPODIR}; \
     echo -e "[eos-artifacts]\nname=EOS artifacts\nbaseurl=file://${EOSREPODIR}\ngpgcheck=0\nenabled=1\npriority=1" >> /etc/yum.repos.d/eos.repo; \
     yum -y --nogpg install \
-    quarkdb eos-server eos-testkeytab eos-archive eos-client \
+    eos-server eos-testkeytab eos-archive eos-client \
     eos-debuginfo eos-fuse eos-fusex eos-test
 
 ENTRYPOINT ["/bin/bash"]