Releasing 1.5.2 for VOLTHA 2.7

Change-Id: Ibd84cce47f20bb808232e532bab2551c7785ce08
diff --git a/VERSION b/VERSION
index 4bb2004..4cda8f1 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.2-dev
+1.5.2