Removed support for Node.js < 4

.travis.yml

@@ -1,13 +1,13 @@
 language: node_js
 sudo: false
 node_js:
-  - "4.2"
-  - "0.12"
-  - "0.11"
-  - "0.10"
+  - "9"
+  - "8"
+  - "6"
+  - "4"
 matrix:
   allow_failures:
-    - node_js: "0.11"
+    - node_js: "9"
 
 # Set up `apt` for `canvassmith`, based on `node-canvas` dependencies
 # https://github.com/Automattic/node-canvas/blob/v1.3.0/.travis.yml#L14-L19
@@ -30,4 +30,8 @@ before_install:
   - npm install -g [email protected]
 
 notifications:
-  email: false
+  email:
+    recipients:
+      - [email protected]
+    on_success: change
+    on_failure: change

package.json

@@ -21,7 +21,7 @@
   "license": "MIT",
   "main": "src/smith.js",
   "engines": {
-    "node": ">= 0.10.0"
+    "node": ">= 4.0.0"
   },
   "scripts": {
     "precheck": "twolfson-style precheck src/ src-test/",