Update CI configs.

* Remove 0.12, 5.0 and io.js; add node 7.0.
* Cache node_modules folder

.travis.yml

@@ -1,11 +1,16 @@
-language: node_js
-
 sudo: false
 
+language: node_js
+
 node_js:
-  - "4"
-  - "0.12"
   - "0.10"
+  - "4"
+  - "6"
+  - "7"
 
 matrix:
   fast_finish: true
+
+cache:
+  directories:
+    - node_modules

appveyor.yml

@@ -1,28 +1,33 @@
-# AppVeyor file
-# http://www.appveyor.com/docs/appveyor-yml
+clone_depth: 10
 
 version: "{build}"
 
-clone_depth: 10
-
+# What combinations to test
 environment:
   matrix:
-    - nodejs_version: "4"
-    - nodejs_version: "0.12"
     - nodejs_version: "0.10"
+      platform: x86
+    - nodejs_version: "4"
+      platform: x64
+    - nodejs_version: "4"
+      platform: x86
+    - nodejs_version: "6"
+      platform: x86
+    - nodejs_version: "7"
+      platform: x86
 
 install:
-  - ps: Install-Product node $env:nodejs_version
+  - ps: Install-Product node $env:nodejs_version $env:platform
   - npm install
 
-build: off
-
 test_script:
   - node --version && npm --version
   - npm test
 
+build: off
+
 matrix:
   fast_finish: true
 
 cache:
-  - 'node_modules -> package.json'              # local npm modules
+  - node_modules -> package.json