Always fire webhook notification on success

So that travis-rubies can build a new binary package.

Author: BanzaiMan

.travis.yml

@@ -86,5 +86,5 @@ notifications:
     urls:
       - "https://rubies.travis-ci.org/rebuild/jruby-head"
 # we are on a branch
-    #on_success: always
+    on_success: always
     on_failure: never