Drop Node 0.10.x & 0.12.x support

See #442.

.travis.yml

@@ -1,8 +1,6 @@
 sudo: false
 language: node_js
 node_js:
-  - "0.10"
-  - "0.12"
   - "4.0"
   - "5.0"
   - "6.0"

README.md

@@ -495,7 +495,7 @@ Compatibility
 Both the parser generator and generated parsers should run well in the following
 environments:
 
-  * Node.js 0.10.0+
+  * Node.js 4+
   * Internet Explorer 8+
   * Edge
   * Firefox

package.json

@@ -55,6 +55,6 @@
     "uglify-js": "2.7.0"
   },
   "engines": {
-    "node": ">=0.10"
+    "node": ">=4"
   }
 }