Add Newton repo details

Now that Newton has been released we need to document how to install
it.  This adds the requisite newton admonition and repo setup.

Change-Id: If76abdffde5c1a1959da8422ac5bd4f556c0956e

doc/source/index.rst

@@ -86,6 +86,11 @@ Linux (RHEL). These steps are marked as follows:
 
    Step that should only be run when installing from the Mitaka stable branch.
 
+.. admonition:: Newton
+   :class: newton
+
+   Step that should only be run when installing from the Newton stable branch.
+
 .. admonition:: SSL
    :class: ssl
 

doc/source/repositories.txt

@@ -54,6 +54,32 @@
                sudo yum -y install --enablerepo=extras centos-release-ceph-hammer
                sudo sed -i -e 's%gpgcheck=.*%gpgcheck=0%' /etc/yum.repos.d/CentOS-Ceph-Hammer.repo
 
+      .. admonition:: Newton
+         :class: newton mton
+
+         Enable latest RDO Newton Delorean repository for all packages
+
+         ::
+
+            sudo curl -L -o /etc/yum.repos.d/delorean-newton.repo https://trunk.rdoproject.org/centos7-newton/current/delorean.repo
+
+         Enable the Newton Delorean Deps repository
+
+         ::
+
+            sudo curl -L -o /etc/yum.repos.d/delorean-deps-newton.repo http://trunk.rdoproject.org/centos7-newton/delorean-deps.repo
+
+         .. admonition:: Ceph
+            :class: ceph
+
+            Enable the CentOS Storage SIG Ceph/Jewel repository if using Ceph
+
+            ::
+
+               sudo yum -y install --enablerepo=extras centos-release-ceph-jewel
+               sudo sed -i -e 's%gpgcheck=.*%gpgcheck=0%' /etc/yum.repos.d/CentOS-Ceph-Jewel.repo
+
+
    Enable last known good RDO Trunk Delorean repository for core openstack packages
 
    ::