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/vendor/gopkg.in/yaml.v2/yamlh.go b/vendor/gopkg.in/yaml.v2/yamlh.go
index e25cee5..f6a9c8e 100644
--- a/vendor/gopkg.in/yaml.v2/yamlh.go
+++ b/vendor/gopkg.in/yaml.v2/yamlh.go
@@ -579,6 +579,7 @@
 
 	simple_key_allowed bool                // May a simple key occur at the current position?
 	simple_keys        []yaml_simple_key_t // The stack of simple keys.
+	simple_keys_by_tok map[int]int         // possible simple_key indexes indexed by token_number
 
 	// Parser stuff