Add node v4 and v5 to travis config

Author: fanatid

.travis.yml

@@ -1,10 +1,18 @@
+sudo: false
+os:
+  - linux
 language: node_js
 node_js:
   - "0.10"
+  - "0.11"
   - "0.12"
-  - "iojs"
+  - "4"
+  - "5"
 env:
-  - TEST_SUITE=lint
-  - TEST_SUITE=unit
-script: "npm run-script $TEST_SUITE"
-
+  matrix:
+    - TEST_SUITE=unit
+matrix:
+  include:
+    - node_js: "4"
+      env: TEST_SUITE=lint
+script: npm run $TEST_SUITE