VOL-2017 voltha-lib moved from voltha-go;
release version 2.2.1

Based on voltha-go commit 5259f8e52b3e3f5c7ad422a4b0e506e1d07f6b36

Change-Id: I8bbecdf456e420714a4016120eafc0d237c80565
diff --git a/VERSION b/VERSION
new file mode 100644
index 0000000..c043eea
--- /dev/null
+++ b/VERSION
@@ -0,0 +1 @@
+2.2.1