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/google.golang.org/grpc/grpclog/loggerv2.go b/vendor/google.golang.org/grpc/grpclog/loggerv2.go
index d493257..23612b7 100644
--- a/vendor/google.golang.org/grpc/grpclog/loggerv2.go
+++ b/vendor/google.golang.org/grpc/grpclog/loggerv2.go
@@ -24,6 +24,8 @@
 	"log"
 	"os"
 	"strconv"
+
+	"google.golang.org/grpc/internal/grpclog"
 )
 
 // LoggerV2 does underlying logging work for grpclog.
@@ -65,7 +67,8 @@
 // SetLoggerV2 sets logger that is used in grpc to a V2 logger.
 // Not mutex-protected, should be called before any gRPC functions.
 func SetLoggerV2(l LoggerV2) {
-	logger = l
+	grpclog.Logger = l
+	grpclog.DepthLogger, _ = l.(grpclog.DepthLoggerV2)
 }
 
 const (
@@ -193,3 +196,19 @@
 func (g *loggerT) V(l int) bool {
 	return l <= g.v
 }
+
+// DepthLoggerV2 logs at a specified call frame. If a LoggerV2 also implements
+// DepthLoggerV2, the below functions will be called with the appropriate stack
+// depth set for trivial functions the logger may ignore.
+//
+// This API is EXPERIMENTAL.
+type DepthLoggerV2 interface {
+	// InfoDepth logs to INFO log at the specified depth. Arguments are handled in the manner of fmt.Print.
+	InfoDepth(depth int, args ...interface{})
+	// WarningDepth logs to WARNING log at the specified depth. Arguments are handled in the manner of fmt.Print.
+	WarningDepth(depth int, args ...interface{})
+	// ErrorDetph logs to ERROR log at the specified depth. Arguments are handled in the manner of fmt.Print.
+	ErrorDepth(depth int, args ...interface{})
+	// FatalDepth logs to FATAL log at the specified depth. Arguments are handled in the manner of fmt.Print.
+	FatalDepth(depth int, args ...interface{})
+}