Add 18.04 to list of links in sidebar navigation

source/conf-common.py

@@ -16,7 +16,7 @@ import sys, os, datetime
 
 html_context = {
   #mahara_releases is used to build the user manual links
-  'mahara_releases': ['17.10', '17.04', '16.10', '16.04', '15.10', '15.04', '1.10', '1.9', '1.8', '1.7', '1.6', '1.5', '1.4']
+  'mahara_releases': ['18.04', '17.10', '17.04', '16.10', '16.04', '15.10', '15.04', '1.10', '1.9', '1.8', '1.7', '1.6', '1.5', '1.4']
 }
 
 # If extensions (or modules to document with autodoc) are in another directory,