Set Gerrit to 3.15.0-rc0

Change-Id: Ibea1beadcbfd432265c48811608c7551961222be
diff --git a/Version.mk b/Version.mk
index 97792e4..2f0f6cd 100644
--- a/Version.mk
+++ b/Version.mk
@@ -1,4 +1,4 @@
-VERSION=3.14.4
-WAR_VERSION=3.14.4
-BRANCH=stable-3.14
-RELEASE=1
+VERSION=3.15.0
+WAR_VERSION=3.15.0-rc0
+BRANCH=stable-3.15
+RELEASE=0rc0