Merge branch 'azure-cleanup-test' of https://github.com/docusign/code-examples-csharp-private

Author: karissarjacobsen

azure-pipelines.yml

@@ -86,6 +86,14 @@ steps:
 
 - script: dir $(Build.SourcesDirectory)/code-examples-csharp-private
 
+- task: CmdLine@2
+  inputs:
+    script: 'docker rm -f $(docker ps -a -q)' 
+
+- script: |
+    docker system prune -a --force
+  displayName: "cleanup docker files"
+
 - task: Docker@2
   displayName: Build csharp image
   inputs: