Update version for 1.6.0-rc3

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/VERSION b/VERSION
index fc7c9a4..daeb9f5 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.92
+1.5.93