Added deprecation message

Author: alvagante

README.md

@@ -1,3 +1,12 @@
+# Deprecation notice
+
+This module was designed for Puppet versions 2 and 3. It should work also on Puppet 4 but doesn't use any of its features.
+
+The current Puppet 3 compatible codebase is no longer actively maintained by example42.
+
+Still, Pull Requests that fix bugs or introduce backwards compatible features will be accepted.
+
+
 # Puppet module: apache
 
 This is a Puppet apache module from the second generation of Example42 Puppet Modules.