CB-14072 Update supported Node.js versions

.travis.yml

@@ -10,6 +10,10 @@ env:
     global:
         # Keep gradle from crapping all over the log
         - TERM=dumb
+    matrix:
+        - nodejs_version=6
+        - nodejs_version=8
+        - nodejs_version=10
 
 install:
     # Install a sdkmanager version that supports the --licenses switch and
@@ -18,7 +22,7 @@ install:
     - yes | sdkmanager tools > /dev/null
     - yes | sdkmanager --licenses > /dev/null
 
-    - nvm install 6
+    - nvm install $nodejs_version
     - npm install
     - npm install -g codecov
 

appveyor.yml

@@ -8,9 +8,9 @@ environment:
     SDK_TOOLS_URL: https://dl.google.com/android/repository/sdk-tools-windows-3859397.zip
 
     matrix:
-        - nodejs_version: 4
         - nodejs_version: 6
         - nodejs_version: 8
+        - nodejs_version: 10
 
 install:
     # Install Android SDK Tools

package.json

@@ -60,7 +60,7 @@
     "rewire": "^2.1.3"
   },
   "engines": {
-    "node": ">=4.0.0"
+    "node": ">=6.0.0"
   },
   "engineStrict": true
 }