Add feature test master and feature test jobs for Centos

Change-Id: Ia3e9aa5a1197088cdf1297c0c40a3bd507a53632
diff --git a/jjb/airship/job_master_feature_tests_ubuntu.yml b/jjb/airship/job_master_feature_tests_ubuntu.yml
index c130f25..9932845 100644
--- a/jjb/airship/job_master_feature_tests_ubuntu.yml
+++ b/jjb/airship/job_master_feature_tests_ubuntu.yml
@@ -71,7 +71,7 @@
         description: 'Distribution to use for the target host.'
     - string:
         name: TARGET_NODE_MEMORY
-        default: 8192
+        default: 4096
         description: 'RAM size of the target host.'
     - string:
         name: NUM_NODES