Cover bridge physnet mapping for Ironic

Ironic in flat scenario require a separate neutron flat network.
This patch adds physnet3:br-baremetal to bridge_mappings when
neutron.gateway.ironic_enabled is defined

Change-Id: I3f2db74e7e34310de19a44739828a874a5d5abac
diff --git a/README.rst b/README.rst
index d3a64ae..c01b822 100644
--- a/README.rst
+++ b/README.rst
@@ -8,7 +8,7 @@
 
 Starting in the Folsom release, Neutron is a core and supported part of the
 OpenStack platform (for Essex, we were an "incubated" project, which means use
-is suggested only for those who really know what they're doing with Neutron). 
+is suggested only for those who really know what they're doing with Neutron).
 
 Sample Pillars
 ==============
@@ -125,11 +125,11 @@
 
 This use case describes a model utilising VxLAN overlay with DVR. The DVR
 routers will only be utilized for traffic that is router within the cloud
-infrastructure and that remains encapsulated. External traffic will be 
-routed to via the network nodes. 
+infrastructure and that remains encapsulated. External traffic will be
+routed to via the network nodes.
 
-The intention is that each tenant will require at least two (2) vrouters 
-one to be utilised 
+The intention is that each tenant will require at least two (2) vrouters
+one to be utilised
 
 Neutron Server
 
@@ -201,7 +201,7 @@
           tenant_network_types: "flat,vxlan"
           mechanism:
             ovs:
-              driver: openvswitch  
+              driver: openvswitch
 
 Compute Node
 
@@ -224,7 +224,7 @@
         external_access: false # Compute node with DVR for east-west only, Network Node has True as default
         metadata:
           host: 127.0.0.1
-          password: pass       
+          password: pass
         backend:
           engine: ml2
           tenant_network_types: "flat,vxlan"
@@ -312,7 +312,7 @@
           tenant_network_types: "flat,vxlan"
           mechanism:
             ovs:
-              driver: openvswitch  
+              driver: openvswitch
 
 Compute Node
 
@@ -331,7 +331,7 @@
           virtual_host: '/openstack'
         local_ip: 192.168.20.20 # br-mesh ip address
         external_access: False
-        dvr: False      
+        dvr: False
         backend:
           engine: ml2
           tenant_network_types: "flat,vxlan"
@@ -344,8 +344,8 @@
 
 With DVR for East-West and North-South, DVR everywhere, Network node for SNAT.
 
-This section describes a network solution that utilises VxLAN 
-overlay networks with DVR with North-South and East-West. Network 
+This section describes a network solution that utilises VxLAN
+overlay networks with DVR with North-South and East-West. Network
 Node is used only for SNAT.
 
 Neutron Server
@@ -419,7 +419,7 @@
           tenant_network_types: "flat,vxlan"
           mechanism:
             ovs:
-              driver: openvswitch  
+              driver: openvswitch
 
 Compute Node
 
@@ -438,7 +438,7 @@
           virtual_host: '/openstack'
         local_ip: 192.168.20.20 # br-mesh ip address
         dvr: True
-        external_access: True     
+        external_access: True
         agent_mode: dvr
         availability_zone: az1
         metadata: