Travis: enabled IRC notification in #grass (https://docs.travis-ci.com/user/notifications/#Configuring-IRC-notifications)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@72706 15284696-431f-4ddb-bdfa-cd5b030d7da7

.travis.yml

@@ -35,3 +35,5 @@ notifications:
                 - wenzeslaus@gmail.com
             on_success: change
             on_failure: always
+        irc: "chat.freenode.net#grass"
+