Add Congestion Mark scenario

refs #4327

Change-Id: Iabbbe241585378e77d792c74d005a22b0d1440c5
diff --git a/.gitignore b/.gitignore
index 0bb0587..c26d822 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,8 @@
 *.pyo
 /.vagrant/
 /install_helpers/tools/generate-link-object
+/install_helpers/tools/test-congestionmark-consumer
+/install_helpers/tools/test-congestionmark-producer
 /install_helpers/tools/test-nack-consumer
 /install_helpers/tools/test-nexthopfaceid-consumer
 /nfd-integ.box