travis config: move notifications to end

This makes it easier to compare the xjava and xkotlin Travis
configuration files.

.travis.yml

 jdk:
   - oraclejdk8
 
-notifications:
-  webhooks:
-    urls:
-      - https://webhooks.gitter.im/e/5e9ccd41111917b19478
-    on_success: change  # options: [always|never|change] default: always
-    on_failure: always  # options: [always|never|change] default: always
-    on_start: never     # options: [always|never|change] default: always
-
 # http://docs.travis-ci.com/user/migrating-from-legacy
 sudo: false
 
   bundler: true
   directories:
     - $HOME/.gradle/caches/
-    - $HOME/.gradle/wrapper/
+    - $HOME/.gradle/wrapper/
+
+notifications:
+  webhooks:
+    urls:
+      - https://webhooks.gitter.im/e/5e9ccd41111917b19478
+    on_success: change  # options: [always|never|change] default: always
+    on_failure: always  # options: [always|never|change] default: always
+    on_start: never     # options: [always|never|change] default: always