Update default cirros version

Update the default CIRROS_VERSION to 0.3.4, which has better support
for IPv6 and some other bugfixes.

Co-Authored-By: Scott Moser <smoser@ubuntu.com>
Change-Id: I03ee6e1403680fb6c421225a7cadaf8a82edf702
Depends-On: Iac9f108d947ff4a51f99c6e8ad9d1ac5b32c000a
diff --git a/stackrc b/stackrc
index abedb00..076efc1 100644
--- a/stackrc
+++ b/stackrc
@@ -536,7 +536,7 @@
 #IMAGE_URLS="http://smoser.brickies.net/ubuntu/ttylinux-uec/ttylinux-uec-amd64-11.2_2.6.35-15_1.tar.gz" # old ttylinux-uec image
 #IMAGE_URLS="http://download.cirros-cloud.net/${CIRROS_VERSION}/cirros-${CIRROS_VERSION}-${CIRROS_ARCH}-disk.img" # cirros full disk image
 
-CIRROS_VERSION=${CIRROS_VERSION:-"0.3.2"}
+CIRROS_VERSION=${CIRROS_VERSION:-"0.3.4"}
 CIRROS_ARCH=${CIRROS_ARCH:-"x86_64"}
 
 # Set default image based on ``VIRT_DRIVER`` and ``LIBVIRT_TYPE``, either of
diff --git a/tools/xen/README.md b/tools/xen/README.md
index c8f47be..61694e9 100644
--- a/tools/xen/README.md
+++ b/tools/xen/README.md
@@ -97,7 +97,7 @@
     # Download a vhd and a uec image
     IMAGE_URLS="\
     https://github.com/downloads/citrix-openstack/warehouse/cirros-0.3.0-x86_64-disk.vhd.tgz,\
-    http://download.cirros-cloud.net/0.3.2/cirros-0.3.2-x86_64-uec.tar.gz"
+    http://download.cirros-cloud.net/0.3.4/cirros-0.3.4-x86_64-uec.tar.gz"
 
     # Explicitly set virt driver
     VIRT_DRIVER=xenserver