Pull cord-tester images from dockerhub as they are available now on dockerhub.
Change image names to be compatible with dockerhub image names.
Update prerequisites.sh last step to pull all the cord-tester docker images.
This should make the cord-test.py build all step redundant now since images should be available for testing immediately after prerequisites.sh are run.

Change-Id: I64cf664a214924349d6728ca2a52974decdef47f
diff --git a/src/test/setup/cord-test.py b/src/test/setup/cord-test.py
index aa8532b..ae2d336 100755
--- a/src/test/setup/cord-test.py
+++ b/src/test/setup/cord-test.py
@@ -49,7 +49,7 @@
                        )
     basename = 'cord-tester'
     switch_on_olt = False
-    IMAGE = 'cord-test/nose'
+    IMAGE = 'cordtest/nose'
     ALL_TESTS = ('tls', 'dhcp', 'dhcprelay','igmp', 'subscriber',
     'cordSubscriber', 'vrouter', 'flows', 'proxyarp', 'acl', 'xos', 'fabric',
     'cbench', 'cluster', 'netCondition', 'cordvtn', 'iperf', 'mini', 'vsg')
@@ -363,7 +363,7 @@
 
     def modify_scapy_files_for_specific_tests(self):
         name = self.name
-        container_cmd_exec = Container(name = name, image = 'cord-test/nose')
+        container_cmd_exec = Container(name = name, image = CordTester.IMAGE)
         tty = False
         dckr = Client()
         cmd =  'cp test/src/test/scapy/fields.py /usr/local/lib/python2.7/dist-packages/scapy/fields.py '
diff --git a/src/test/setup/prerequisites.sh b/src/test/setup/prerequisites.sh
index 1cbea42..4874838 100755
--- a/src/test/setup/prerequisites.sh
+++ b/src/test/setup/prerequisites.sh
@@ -117,3 +117,9 @@
     service openvswitch-switch stop
     install_ovs
 fi
+
+test_images=(cordtest/radius:candidate cordtest/quagga:candidate cordtest/nose:candidate)
+for img in ${test_images[*]}; do
+    echo "Pulling cord-tester image $img"
+    docker pull $img 2>/dev/null
+done