Add Dockerfile with the proper path for importing packages built against the latest XRootD server

Dockerfile_xrd_testing

+#
+# Simple EOS Docker file
+#
+# Version 0.2
+
+FROM centos:7
+MAINTAINER Elvin Sindrilaru, esindril@cern.ch, CERN 2017
+
+# Add extra repositories
+ADD eos-docker/*.repo /etc/yum.repos.d/
+
+# Add helper scripts
+ADD eos-docker/image_scripts/*.sh /
+
+# Add configuration files for EOS instance
+ADD eos-docker/eos.sysconfig /etc/sysconfig/eos
+ADD eos-docker/xrd.cf.* eos-docker/krb5.conf /etc/
+ADD eos-docker/fuse.conf /etc/eos/fuse.conf
+ADD eos-docker/fstfmd.dict /var/eos/md/
+
+RUN mkdir /var/tmp/eosxd-cache/ /var/tmp/eosxd-journal/
+RUN useradd eos-user
+
+# Docker will aggressively cache the following command, but this is fine, since
+# these packages are not updated often.
+RUN yum -y --nogpg install \
+    heimdal-server heimdal-workstation \
+    krb5-workstation yum-plugin-priorities \
+    createrepo initscripts less nano \
+    git parallel compat-libf2c-34 libgfortran \
+    gdb gcc-c++ cmake3 libacl-devel perl-Test-Harness \
+    rpm-build bzip2 automake autoconf libtool sudo
+
+# 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_xrd_testing ${EOSREPODIR}
+
+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 \
+    eos-server eos-testkeytab eos-archive eos-client \
+    eos-debuginfo eos-fuse eos-fusex eos-test
+
+ENTRYPOINT ["/bin/bash"]