build: support Node.js 4.x

closes #2751
closes #2754
closes #2757

.travis.yml

@@ -5,6 +5,7 @@ node_js:
   - "1.8"
   - "2.5"
   - "3.3"
+  - "4.2"
 sudo: false
 before_install: "npm rm --save-dev connect-redis"
 script: "npm run-script test-ci"

appveyor.yml

@@ -5,6 +5,7 @@ environment:
     - nodejs_version: "1.8"
     - nodejs_version: "2.5"
     - nodejs_version: "3.3"
+    - nodejs_version: "4.2"
 install:
   - ps: Install-Product node $env:nodejs_version
   - npm rm --save-dev connect-redis