VOL-2348 Update voltha-openolt-adapter to latest voltha-lib-go;
I/O Errors should trigger unreadiness;
Update tech profile mocks

Change-Id: If245ab38050962af5992e8f0b67823c39e9522e8
diff --git a/VERSION b/VERSION
index f963933..bda8fbe 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.6-dev
+2.2.6