[Tests] clean up travis.yml

.travis.yml

 language: node_js
 node_js:
-  - "5.1"
-  - "5.0"
+  - "6"
+  - "5"
+  - "4"
   - "4.2"
-  - "4.1"
-  - "4.0"
-script: npm run lint && npm test
+  - "iojs"
+script: 'if [ "${TRAVIS_NODE_VERSION}" = 6 ]; then npm test; else npm run tests-only; fi'
 env:
   - REACT=0.14
 sudo: false
 matrix:
   fast_finish: true
   allow_failures:
-    - node_js: "5.0"
-    - node_js: "4.1"
-    - node_js: "4.0"
-    - node_js: "0.11"
+    - node_js: "iojs"

package.json

@@ -11,7 +11,9 @@
     "clean": "rimraf lib",
     "lint": "eslint --ext .js,.jsx src test",
     "mocha": "mocha --compilers js:babel-register,jsx:babel-register --require airbnb-js-shims --recursive ./test/_helpers",
-    "test": "npm run mocha --silent test",
+    "pretest": "npm run --silent lint",
+    "tests-only": "npm run mocha --silent test",
+    "test": "npm run tests-only",
     "storybook": "start-storybook -p 9001 -s ./public",
     "tag": "git tag v$npm_package_version",
     "gh-pages:clean": "rm -rf _gh-pages",