SEBA-902 single-olt tests;
Pin protoc-gen-go to 1.3.2 to resolve compatibility issue;
Run go mod tidy / go mod vendor on importer;
Add Go Module support to demotest

Change-Id: Ifde824fc9a6317b0adc1e12bea54ee1f9b788906
diff --git a/demo_test/vendor/github.com/Shopify/sarama/Vagrantfile b/demo_test/vendor/github.com/Shopify/sarama/Vagrantfile
new file mode 100644
index 0000000..07d7ffb
--- /dev/null
+++ b/demo_test/vendor/github.com/Shopify/sarama/Vagrantfile
@@ -0,0 +1,14 @@
+# We have 5 * 192MB ZK processes and 5 * 320MB Kafka processes => 2560MB
+MEMORY = 3072
+
+Vagrant.configure("2") do |config|
+  config.vm.box = "ubuntu/bionic64"
+
+  config.vm.provision :shell, path: "vagrant/provision.sh"
+
+  config.vm.network "private_network", ip: "192.168.100.67"
+
+  config.vm.provider "virtualbox" do |v|
+    v.memory = MEMORY
+  end
+end