improvement: travis versions

Author: Josef Fröhle c5252118

.travis.yml

@@ -4,10 +4,8 @@ node_js:
   - "0.10"
   - "0.12"
   - "4"
-  - "5"
-  - "iojs-v1.8"
-  - "iojs-v2.5"
-  - "iojs-v3.3"
+  - "6"
+  - "7"
 before_install:
   - npm install -g grunt-cli
 notifications: