Preparing for 3.0.0 Havana release

Updated Modulefile version.
Updated README.md release notes.

Change-Id: I7779538be1db2391c62903fada27128af17fd908

Author: Chris Hoge

Modulefile

@@ -1,5 +1,5 @@
 name    'puppetlabs-horizon'
-version '2.2.0'
+version '3.0.0-rc1'
 source  'https://github.com/stackforge/puppet-horizon'
 author  'Puppet Labs'
 license 'Apache License 2.0'

README.md

@@ -85,6 +85,15 @@ Contributors
 Release Notes
 -------------
 
+**3.0.0**
+
+* Major release for OpenStack Havana
+* Updated user and group for Debian family OSes.
+* Updated policy files for RedHat family OSes.
+* Enabled SSL support with cert/key.
+* Improved default logging configuration.
+* Fixed bug to set LOGOUT_URL properly.
+
 **2.2.0**
 
 * Fixed apache 0.9.0 incompatability.