Update build image

Author: danielunderwood

Diff for: azure-pipelines.yml

@@ -16,15 +16,15 @@ jobs:
 - job:
   displayName: Setup
   pool:
-    vmImage: 'Ubuntu-18.04'
+    vmImage: 'Ubuntu-20.04'
   steps:
   - powershell: Write-Host "##vso[build.updatebuildnumber]$($env:VERSION)"
     displayName: Set Build Name
 
 - job:
   displayName: Build postgres
   pool:
-    vmImage: 'Ubuntu-18.04'
+    vmImage: 'Ubuntu-20.04'
   steps:
   - task: Docker@2
     displayName: Build image
@@ -41,7 +41,7 @@ jobs:
 - job:
   displayName: Build server
   pool:
-    vmImage: 'Ubuntu-18.04'
+    vmImage: 'Ubuntu-20.04'
   steps:
   - task: Docker@2
     displayName: Build image