Add ngx_http_limit_conn_module functionality

Add posibility to limit the number of connections per the defined key

Change-Id: Ic05f9c4a4904ea4293889bc3d88d0122525df1b0
Related-Prod: PROD-24400
diff --git a/tests/pillar/proxy_rate_limit.sls b/tests/pillar/proxy_rate_limit.sls
index 7dc7156..7cebd59 100644
--- a/tests/pillar/proxy_rate_limit.sls
+++ b/tests/pillar/proxy_rate_limit.sls
@@ -42,6 +42,21 @@
           size: 10m
           rate: '1r/s'
       limit_req_status: 503
+    limit_conn_module:
+      limit_conn_zone:
+        global_limit_conn_zone:
+          key: 'binary_remote_addr'
+          size: 20m
+          enabled: true
+        openstack_web_conn_zone:
+          key: 'binary_remote_addr'
+          size: 10m
+          enabled: true
+      limit_conn:
+        global_limit_conn_zone:
+          connections: 100
+          enabled: true
+      limit_conn_status: 503
     site:
       nginx_proxy_site01:
         enabled: true
@@ -59,3 +74,9 @@
              global_limit_zone:
                burst: 5
                enabled: true
+        limit_conn_module:
+          limit_conn:
+            openstack_web_conn_zone:
+              connections: 50
+              enabled: true
+          limit_conn_status: 503