Set next Gerrit version to 3.0

Change-Id: I38512eb1e6b4dedb91b86863b730a2bc3c6e1fc0

src/main/java/com/googlesource/gerrit/plugins/manager/GerritVersionBranch.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/manager/GerritVersionBranch.java b/src/main/java/com/googlesource/gerrit/plugins/manager/GerritVersionBranch.java
index debe679..6a36133 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/manager/GerritVersionBranch.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/manager/GerritVersionBranch.java
@@ -15,7 +15,7 @@
 package com.googlesource.gerrit.plugins.manager;
 
 public class GerritVersionBranch {
-  private static final String GERRIT_NEXT_VERSION = "2.16";
+  private static final String GERRIT_NEXT_VERSION = "3.0";
 
   public static String getBranch(String gerritVersion) {
     if (gerritVersion == null