fix(appveyor): add workaround for webdriver bug (angular#2862)

See angular/webdriver-manager#107 for context.
Should be reverted once issue is fixed.

Author: filipesilva

.appveyor.yml

@@ -7,7 +7,7 @@ matrix:
   fast_finish: true
 
 install:
-  - ps: Install-Product node $env:nodejs_version
+  - ps: Install-Product node $env:nodejs_version x64
   - npm install -g npm
   - npm install