Use pool syntax

Author: vijaymatest1

azure-pipelines.acr.yml

@@ -1,7 +1,7 @@
 # Build Docker image for this app using Azure Pipelines
 # https://docs.microsoft.com/azure/devops/pipelines/languages/docker?view=vsts
-
-queue: 'Hosted Linux Preview'
+pool:
+  vmImage: 'Ubuntu 16.04'
 
 variables:
   imageName: 'nodejssample:$(Build.BuildId)'

azure-pipelines.docker.yml

@@ -1,8 +1,8 @@
 # Build Docker image for this app using Azure Pipelines
 # https://docs.microsoft.com/azure/devops/pipelines/languages/docker?view=vsts
-
-queue: 'Hosted Linux Preview'
-
+pool:
+  vmImage: 'Ubuntu 16.04'
+  
 variables:
   imageName: 'nodejssample:$(Build.BuildId)'
   # define two more variables dockerId and dockerPassword in the build pipeline in UI

azure-pipelines.yml

@@ -1,8 +1,8 @@
 # Build NodeJS Express app using Azure Pipelines
 # https://docs.microsoft.com/azure/devops/pipelines/languages/javascript?view=vsts
-
-queue: 'Hosted Linux Preview'
-
+pool:
+  vmImage: 'Ubuntu 16.04'
+  
 steps:
 - task: NodeTool@0
   inputs: