Update hosted image (#715)

* build: update to 2019

* different build

* different build

vsts/node-nightly-df.yaml

@@ -61,7 +61,7 @@ phases:
   displayName: Windows Build - Node 8
   condition: succeededOrFailed()
   queue:
-    name: Hosted VS2017
+    name: Hosted
   steps:
   - task: NodeTool@0
     displayName: 'Use Node 8.10.x'