Add Node 10 & Drop Node 4 Support
diff --git a/.travis.yml b/.travis.yml
index b151b0b..c912dd7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,19 @@
 language: objective-c
 sudo: false
+
+env:
+  matrix:
+    - TRAVIS_NODE_VERSION: '6'
+    - TRAVIS_NODE_VERSION: '8'
+    - TRAVIS_NODE_VERSION: '10'
+
+before_install:
+  - nvm install $TRAVIS_NODE_VERSION
+
 install:
-- npm install
-script: "npm test"
\ No newline at end of file
+  - npm install
+
+script:
+  - node --version
+  - npm --version
+  - npm test
diff --git a/package.json b/package.json
index 0e2dd06..cc16d1a 100644
--- a/package.json
+++ b/package.json
@@ -54,5 +54,8 @@
     "nodeunit": "^0.8.7",
     "tmp": "^0.0.26",
     "uncrustify": "^0.6.1"
+  },
+  "engines": {
+    "node": ">=6.0.0"
   }
 }