[VOL-4290] Voltha go library updates for gRPC migration

Change-Id: I1aa2774beb6b7ed7419bc45aeb53fcae8a8ecda0
diff --git a/vendor/github.com/sirupsen/logrus/terminal_check_unix.go b/vendor/github.com/sirupsen/logrus/terminal_check_unix.go
new file mode 100644
index 0000000..cc4fe6e
--- /dev/null
+++ b/vendor/github.com/sirupsen/logrus/terminal_check_unix.go
@@ -0,0 +1,13 @@
+// +build linux aix
+// +build !js
+
+package logrus
+
+import "golang.org/x/sys/unix"
+
+const ioctlReadTermios = unix.TCGETS
+
+func isTerminal(fd int) bool {
+	_, err := unix.IoctlGetTermios(fd, ioctlReadTermios)
+	return err == nil
+}