Docs: Configure firewall to allow testing of baremetal

Due to Docker's iptables configuration, it is now necessary to modify
iptables in order to test bare metal provisioning using Tenks. Update
the development instructions accordingly.

Change-Id: I598066ff2574ff572a88d351e3b4d734a824ae93

doc/source/development/automated.rst

@@ -143,6 +143,11 @@ Verify that VirtualBMC is running::
 
     ~/tenks-venv/bin/vbmc list
 
+Configure the firewall to allow the baremetal nodes to access OpenStack
+services::
+
+    ./dev/configure-firewall.sh
+
 We are now ready to run the ``dev/overcloud-test-baremetal.sh`` script. This
 will run the ``init-runonce`` setup script provided by Kolla Ansible that
 registers images, networks, flavors etc. It will then deploy a bare metal