cleaning in same line as install to limit number of layers + remove cta...

cleaning in same line as install to limit number of layers + remove cta package (installed later so that we have just one docker image

continuousintegration/docker/ctafrontend/cc7/Dockerfile

@@ -39,8 +39,9 @@ ADD build_rpm/RPM ${CTAREPODIR}
 RUN createrepo ${CTAREPODIR}; echo -e "[cta-artifacts]\nname=CTA artifacts\nbaseurl=file://${CTAREPODIR}\ngpgcheck=0\nenabled=1\npriority=2" > /etc/yum.repos.d/cta-artifacts.repo
 
 # Install needed packages
-RUN yum -y install cta-frontend cta-debuginfo cgdb less psmisc lynx strace ltrace
-RUN yum clean all
+#RUN yum -y install cta-frontend cta-debuginfo cgdb less psmisc lynx strace ltrace
+RUN yum -y install cgdb less psmisc lynx strace ltrace && yum clean all
+#RUN yum clean all
 
 # Static configuration files
 ADD ${BASEDIR}/etc/xrootd/xrootd-cta.cfg /etc/xrootd/xrootd-cta.cfg