Added some installation scripts for CentOS. Will ease the definition of Dockerfiles

docker/setup_cpan.CentOS-7.sh

+#!/bin/bash
+
+set -e
+
+# We should probably install some build packages
+
+for arg
+do
+	cpanm --installdeps --with-recommends "$arg"
+done
+

docker/setup_os.CentOS-7.sh

+#!/bin/bash
+
+set -e
+
+# Proc::Daemon trick: we need version 0.23 but only version 0.19 is in the
+# centos archives. cpanm will fail building 0.23 if 0.19 is around, so we
+# need to build 0.23 before we install anything else
+yum install -y perl-App-cpanminus perl-Test-Simple perl-Proc-ProcessTable
+tmpdir=$(mktemp -d)
+echo "requires 'Proc::Daemon', '0.23';" > "$tmpdir/cpanfile"
+cpanm --installdeps --notest --with-recommends "$tmpdir"
+rmdir "$tmpdir"
+
+# install required extra software
+yum install -y curl \
+	       sqlite perl-DBD-SQLite postgresql perl-DBD-Pg mariadb perl-DBD-MySQL perl-DBI \
+               perl-Capture-Tiny perl-DateTime perl-Time-Piece perl-HTML-Parser perl-JSON \
+               perl-Test-Exception perl-Test-Simple perl-Test-Warn perl-Test-Warnings perl-Test-File-Contents perl-Test-Perl-Critic perl-GraphViz \
+               gnuplot perl-BSD-Resource
+