fix: use ubuntu-latest for build pipelines

build/ci-build.yml

@@ -40,7 +40,7 @@ stages:
     jobs:
       - job: Compile
         pool:
-          vmImage: 'ubuntu-16.04'
+          vmImage: '$(Vm.Image)'
         steps:
           - template: 'nuget/determine-pr-version.yml@templates'
             parameters:
@@ -68,7 +68,7 @@ stages:
       - job: UnitTests
         displayName: 'Run unit tests'
         pool:
-          vmImage: 'ubuntu-16.04'
+          vmImage: '$(Vm.Image)'
         steps:
           - task: DownloadPipelineArtifact@2
             displayName: 'Download build artifacts'
@@ -88,7 +88,7 @@ stages:
       - job: IntegrationTests
         displayName: 'Run integration tests'
         pool:
-          vmImage: 'ubuntu-16.04'
+          vmImage: '$(Vm.Image)'
         steps:
           - task: DownloadPipelineArtifact@2
             displayName: 'Download build artifacts'
@@ -111,7 +111,7 @@ stages:
       - job: PushToMyGet
         displayName: 'Push to MyGet'
         pool:
-          vmImage: 'ubuntu-16.04'
+          vmImage: '$(Vm.Image)'
         steps:
           - task: DownloadPipelineArtifact@2
             displayName: 'Download build artifacts'

build/nuget-release.yml

@@ -32,7 +32,7 @@ stages:
     jobs:
       - job: Compile
         pool:
-          vmImage: 'ubuntu-16.04'
+          vmImage: '$(Vm.Image)'
         steps:
           - template: build/build-solution.yml@templates
             parameters:
@@ -57,7 +57,7 @@ stages:
       - job: UnitTests
         displayName: 'Run unit tests'
         pool:
-          vmImage: 'ubuntu-16.04'
+          vmImage: '$(Vm.Image)'
         steps:
           - task: DownloadPipelineArtifact@2
             displayName: 'Download build artifacts'
@@ -77,7 +77,7 @@ stages:
       - job: IntegrationTests
         displayName: 'Run integration tests'
         pool:
-          vmImage: 'ubuntu-16.04'
+          vmImage: '$(Vm.Image)'
         steps:
           - task: DownloadPipelineArtifact@2
             displayName: 'Download build artifacts'
@@ -99,7 +99,7 @@ stages:
       - job: PushToNuGet
         displayName: 'Push to NuGet.org'
         pool:
-          vmImage: 'ubuntu-16.04'
+          vmImage: '$(Vm.Image)'
         steps:
           - task: DownloadPipelineArtifact@2
             displayName: 'Download build artifacts'

build/variables/build.yml

@@ -1,3 +1,4 @@
 variables:
   DotNet.Sdk.Version: '3.1.201'
-  Project: 'Arcus.BackgroundJobs'
+  Project: 'Arcus.BackgroundJobs'
+  Vm.Image: 'ubuntu-latest'