Add ability to disable apache modules

Introduce a new pillar apache:server:mods that is a dictionary with
the new module metadata. It will allow to manage apache modules by
setting "status: disabled/enabled".

Change-Id: I4ef85ce426f92e01a15e0fbcdb1370d68c1cf736
Related-Prod: PROD-23524
diff --git a/README.rst b/README.rst
index 6578abe..b99b3c1 100644
--- a/README.rst
+++ b/README.rst
@@ -441,6 +441,17 @@
         start_period: 600
         end_period: 1200
 
+Apache modules management
+
+.. code-block:: yaml
+
+  apache:
+    server:
+      mods:
+        status:
+          enabled: True
+          status: 'disabled'
+
 
 More Information
 ================