[VOL-4291] Rw-core updates for gRPC migration

Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/github.com/opentracing/opentracing-go/go.mod b/vendor/github.com/opentracing/opentracing-go/go.mod
new file mode 100644
index 0000000..bf48bb5
--- /dev/null
+++ b/vendor/github.com/opentracing/opentracing-go/go.mod
@@ -0,0 +1,5 @@
+module github.com/opentracing/opentracing-go
+
+go 1.14
+
+require github.com/stretchr/testify v1.3.0