Chore: tweak CI settings

.travis.yml

@@ -1,10 +1,12 @@
 sudo: false
+
 language: node_js
 node_js:
-  - "8"
+  - "4.0.0"
   - "4"
   - "6"
-  - "7"
+  - "8"
+
 script:
   - npm test
 after_success:

appveyor.yml

@@ -1,21 +1,24 @@
+version: '{build}'
+shallow_clone: true
+matrix:
+  fast_finish: true
+
 environment:
   matrix:
-    - nodejs_version: '8'
+    - nodejs_version: '4.0.0'
     - nodejs_version: '4'
     - nodejs_version: '6'
-    - nodejs_version: '7'
+    - nodejs_version: '8'
+
 install:
   - ps: Install-Product node $env:nodejs_version
   - set CI=true
   - set AVA_APPVEYOR=true
+  - node --version
+  - npm --version
   - npm install
-matrix:
-  fast_finish: true
+
 build: off
-version: '{build}'
-shallow_clone: true
-clone_depth: 1
+
 test_script:
-  - node --version
-  - npm --version
   - npm test