added testen and up support node version

Author: Ivan Demidov

.travis.yml

@@ -4,6 +4,8 @@ node_js:
   - "6"
   - "5"
   - "4"
+  - "0.12"
+  - "0.10"
 
 after_script:
   - './node_modules/.bin/nyc report --reporter=text-lcov | ./node_modules/.bin/coveralls'

package.json

@@ -5,14 +5,24 @@
   "main": "lib/index.js",
   "files": "lib/index.js",
   "engines": {
-    "node": ">=4"
+    "node": ">=0.10"
   },
   "scripts": {
     "test": "eslint --format=node_modules/eslint-formatter-pretty ./src/*.js ./test/*.js && nyc ava",
     "clean": "rm -rf lib && mkdir lib",
     "build": "npm run clean && babel src/index.js --out-file lib/index.js",
     "prepublish": "npm run build",
-    "update": "updtr && ava-codemods --force"
+    "update": "updtr && ava-codemods --force",
+    "testen": "testen -n -- ava"
+  },
+  "testen": {
+    "node": [
+      "0.10",
+      "0.12",
+      "4",
+      "5",
+      "6"
+    ]
   },
   "keywords": [
     "postcss",
@@ -54,6 +64,7 @@
     "eslint-plugin-require-path-exists": "^1.1.5",
     "eslint-plugin-xo": "^0.5.0",
     "nyc": "^6.6.0",
+    "testen": "^1.8.2",
     "updtr": "^0.1.10"
   },
   "babel": {