[test] reduce directives

.travis.yml

@@ -1,24 +1,19 @@
 language: node_js
 node_js:
   - "0.10"
-  - "0.11"
   - "0.12"
   - "iojs"
-before_install:
-  - 'if [ "${TRAVIS_NODE_VERSION}" == "0.8" ] || [ "${TRAVIS_NODE_VERSION}" == "0.9" ] ; then npm install -g npm@2.6.0; fi'
 script:
   - "npm run test-travis"
 after_script:
   - "npm install coveralls@2.11.x && cat coverage/lcov.info | coveralls"
 matrix:
   fast_finish: true
   allow_failures:
-    - node_js: "0.9"
-    - node_js: "0.11"
     - node_js: "iojs"
 notifications:
   irc:
-    channels: 
+    channels:
       - "irc.freenode.org#bigpipe"
     on_success: change
     on_failure: change