travis: attempt to fix 0.8, test node v0.12

.travis.yml

@@ -1,9 +1,11 @@
 language: node_js
 node_js:
-  - '0.8'
-  - '0.10'
-  - '0.11'
-  - 'iojs'
+  - "0.8"
+  - "0.10"
+  - "0.12"
+  - "iojs"
 before_install:
+  - '[ "${TRAVIS_NODE_VERSION}" != "0.8" ] || npm install -g npm@1.4.28'
+  - npm install -g npm@latest
   - sudo chown -R $USER /usr/local
   - sh install