ci: update azure build images

Author: phated

.ci/.azure-pipelines.yml

@@ -21,7 +21,7 @@ jobs:
   - job: Test_Windows
     displayName: Run Tests on Windows
     pool:
-      vmImage: vs2017-win2016
+      vmImage: "windows-2019"
     strategy:
       matrix:
         Node_v10:
@@ -36,7 +36,7 @@ jobs:
   - job: Test_MacOS
     displayName: Run Tests on MacOS
     pool:
-      vmImage: macos-10.13
+      vmImage: "macOS-10.15"
     strategy:
       matrix:
         Node_v10: