Merge pull request #11374 from Microsoft/ben/appveyor

build with node 6 to workaround VS 2015 update 3 issue

appveyor.yml

@@ -3,7 +3,8 @@ environment:
   VSCODE_BUILD_VERBOSE: true
 
 install:
-  - ps: Install-Product node 5.10.1 x64
+  - ps: Install-Product node 6.5.0 x64
+  - npm install -g npm
   - npm install -g gulp mocha
 
 build_script:
@@ -12,5 +13,7 @@ build_script:
   - gulp compile
 
 test_script:
+  - node --version
+  - npm --version
   - .\scripts\test.bat
   - .\scripts\test-integration.bat