Disable verify-centos and periodic jobs

The jobs are disabled in order to reduce the queue while
verifying changes. Centos will be looked into once things
stabilize on ubuntu.

Change-Id: If4f2209d9da5523dca12ff013cfc8c71353618a6
diff --git a/jjb/cloud-infra/cloud-infra-verify-engine.yaml b/jjb/cloud-infra/cloud-infra-verify-engine.yaml
index 18f106b..e9a1aa4 100644
--- a/jjb/cloud-infra/cloud-infra-verify-engine.yaml
+++ b/jjb/cloud-infra/cloud-infra-verify-engine.yaml
@@ -50,7 +50,6 @@
     stream:
       - 'master':
           branch: '{stream}'
-          disabled: 'false'
 
     distro:
       - ubuntu1804:
@@ -60,7 +59,7 @@
           unstable: false
           notbuilt: false
       - centos7:
-          disabled: false
+          disabled: true
           successful: true
           failed: true
           unstable: true