Implement rate-limiting to the format `listen`

Moving rate_limit logic to the haproxy/files/_rate_limit.cfg

Change-Id: Iefc4860793a47934703eae8efdcc2f41761f5ae5
Related-Prod: PROD-24396
diff --git a/.kitchen.yml b/.kitchen.yml
index e82b842..8ee5116 100644
--- a/.kitchen.yml
+++ b/.kitchen.yml
@@ -60,4 +60,9 @@
     provisioner:
       pillars-from-files:
         haproxy.sls: tests/pillar/stats.sls
+
+  - name: single_rate_limiting
+    provisioner:
+      pillars-from-files:
+        haproxy.sls: tests/pillar/single_rate_limiting.sls
 # vim: ft=yaml sw=2 ts=2 sts=2 tw=125