Dropping support for node 0.8

node 0.8 on Travis CI will not run npm update before testing, for
unknown reasons. If anybody *needs* 0.8 support, open an issue and I’ll
see what I can do as far as contacting Travis CI about a resolution.

.travis.yml

@@ -1,8 +1,8 @@
 language: node_js
 node_js:
+  - "0.12"
   - "0.11"
   - "0.10"
-  - "0.8"
 script: './node_modules/.bin/grunt travis'
 before_script:
   - npm update -g npm