Update for action version.

See https://github.com/apache/openwhisk/pull/4761.
diff --git a/tests/dotnetshared/Environment.cs b/tests/dotnetshared/Environment.cs
index d3a1988..cd68d2a 100644
--- a/tests/dotnetshared/Environment.cs
+++ b/tests/dotnetshared/Environment.cs
@@ -28,6 +28,7 @@
             message.Add("api_key", new JValue(System.Environment.GetEnvironmentVariable("__OW_API_KEY")));
             message.Add("namespace", new JValue(System.Environment.GetEnvironmentVariable("__OW_NAMESPACE")));
             message.Add("action_name", new JValue(System.Environment.GetEnvironmentVariable("__OW_ACTION_NAME")));
+            message.Add("action_version", new JValue(System.Environment.GetEnvironmentVariable("__OW_ACTION_VERSION")));
             message.Add("activation_id", new JValue(System.Environment.GetEnvironmentVariable("__OW_ACTIVATION_ID")));
             message.Add("deadline", new JValue(System.Environment.GetEnvironmentVariable("__OW_DEADLINE")));
             return (message);