Update travis config (appium#10972)

.travis.yml

@@ -1,40 +1,61 @@
 language: node_js
-sudo: false
-env:
-  - CXX=g++-4.8
 addons:
   apt:
     sources:
       - ubuntu-toolchain-r-test
     packages:
       - g++-4.8
+env:
+  global:
+    - CXX=g++-4.8
+node_js: "10"
 jobs:
   include:
-    - name: test
-      node_js:
-        - "9"
-        - "7"
-      script: npm run generate-docs && npm run test && npm run e2e-test
-    - name: bundle
+    - stage: Tests
+      os:
+        - linux
+        - sudo: false
+      script: npm run test && npm run e2e-test
+      node_js: "10"
+    - stage:
+      os:
+        - linux
+        - sudo: false
+      script: npm run test && npm run e2e-test
+      node_js: "8"
+    - stage:
+      os:
+        - linux
+        - sudo: false
+      script: npm run test && npm run e2e-test
+      node_js: "6"
+    - stage:
+      os:
+        - linux
+        - sudo: false
+      env:
+        # this is just to indicate in the Travis job list that this is generating docs
+        - GENERATE_DOCS=true
+      script: npm run generate-docs
+    - stage: BinTray Bundle Build and Upload
+      # only want to run this on the main master branch
+      if: branch = master AND type != pull_request
+      os:
+        - osx
+        - osx_image: xcode9.4
       env:
         - NODE_ENV=production
-      node_js: 9
-      if: branch = master
-      os: osx # Need to use Mac OSX build to build XCUITestDriver
-      osx_image: xcode9.4
-      script:
+      install:
         # Install prod dependencies
         - npm install
 
         # Install only the dev dependencies that we need
         - npm install --only=dev gulp
         - npm install --only=dev appium-gulp-plugins
-
+      before_script:
         # Build the assets
         - npm run build
 
         # Remove the dev depenedencies
-        - npm prune 
-
-        # Zip up and upload this to bintray
-        - npm run zip-and-upload
+        - npm prune
+      script: npm run zip-and-upload