Bump version string to trigger a release build

Change-Id: I2f128b6b0874dc888b7478c35848a0af70b2daac
diff --git a/VERSION b/VERSION
index 78b1ce5..cef2998 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.8.20
\ No newline at end of file
+1.8.21
\ No newline at end of file