Remove testing under 1.8 and add IRC nofications

.travis.yml

@@ -1,7 +1,6 @@
 language: ruby
 script: 'bundle exec rake ci'
 rvm:
-  - 1.8.7
   - 1.9.2
   - 1.9.3
   - 2.0.0
@@ -9,12 +8,12 @@ rvm:
   - rbx-19mode
 matrix:
   allow_failures:
-    # No mutators for 1.8 specifc AST nodes
-    - rvm: rbx-18mode
-    - rvm: 1.8.7
     # We'll see what happens
     - rvm: ruby-head
     - rvm: 2.0.0
 notifications:
-  email:
-    - mbj@seonic.net
+  irc:
+    channels:
+      - irc.freenode.org#datamapper
+    on_success: never
+    on_failure: change