DOC: update documentation for helm test --logs

Signed-off-by: Jeff Knurek <j.knurek@travelaudience.com>

docs/helm/helm_test.md

@@ -21,6 +21,7 @@ helm test [RELEASE] [flags]
       --cleanup               Delete test pods upon completion
   -h, --help                  help for test
       --max uint32            Maximum number of test pods to run in parallel (default 20)
+      --logs                  Dump the logs from test pods (this runs after all tests are complete, but before any cleanup
       --parallel              Run test pods in parallel
       --timeout int           Time in seconds to wait for any individual Kubernetes operation (like Jobs for hooks) (default 300)
       --tls                   Enable TLS for request
@@ -47,4 +48,4 @@ helm test [RELEASE] [flags]
 
 * [helm](helm.md)	 - The Helm package manager for Kubernetes.
 
-###### Auto generated by spf13/cobra on 25-Jul-2019
+###### Auto generated by spf13/cobra on 6-Aug-2019