Add grpcio-testing to Python distribtests
diff --git a/test/distrib/python/test_packages.sh b/test/distrib/python/test_packages.sh
index 6c3a51c..755daa1 100755
--- a/test/distrib/python/test_packages.sh
+++ b/test/distrib/python/test_packages.sh
@@ -32,6 +32,7 @@
 
 HEALTH_ARCHIVES=("$EXTERNAL_GIT_ROOT"/input_artifacts/grpcio-health-checking-[0-9]*.tar.gz)
 REFLECTION_ARCHIVES=("$EXTERNAL_GIT_ROOT"/input_artifacts/grpcio-reflection-[0-9]*.tar.gz)
+TESTING_ARCHIVES=("$EXTERNAL_GIT_ROOT"/input_artifacts/grpcio-testing-[0-9]*.tar.gz)
 
 VIRTUAL_ENV=$(mktemp -d)
 virtualenv "$VIRTUAL_ENV"
@@ -56,6 +57,7 @@
 at_least_one_installs "${TOOLS_ARCHIVES[@]}"
 at_least_one_installs "${HEALTH_ARCHIVES[@]}"
 at_least_one_installs "${REFLECTION_ARCHIVES[@]}"
+at_least_one_installs "${TESTING_ARCHIVES[@]}"
 
 
 #