Run travis-ci tests on iojs and node v0.12; speed up builds; al…

…low 0.8 failures.

.travis.yml

@@ -1,5 +1,8 @@
 language: node_js
 node_js:
+  - "iojs-v1.1"
+  - "iojs-v1.0"
+  - "0.12"
   - "0.11"
   - "0.10"
   - "0.9"
@@ -13,6 +16,7 @@ matrix:
   allow_failures:
     - node_js: "0.11"
     - node_js: "0.9"
+    - node_js: "0.8"
     - node_js: "0.6"
     - node_js: "0.4"
-
+sudo: false