Test travis alerting system

git-svn-id: http://svn.osgeo.org/postgis/trunk@11916 b70326c6-7e19-0410-871a-916f4a2858ee
change to notify only on change or for success and always for failure

git-svn-id: http://svn.osgeo.org/postgis/trunk@11917 b70326c6-7e19-0410-871a-916f4a2858ee