remove Wercker badge

Author: Vladimir Kotal

README.md

@@ -4,7 +4,6 @@ Copyright (c) 2006, 2019 Oracle and/or its affiliates. All rights reserved.
 
 # OpenGrok - a wicked fast source browser
 [![Travis status](https://travis-ci.org/oracle/opengrok.svg?branch=master)](https://travis-ci.org/oracle/opengrok)
-[![wercker status](https://app.wercker.com/status/e2a879f4677e679c0bbf8fa82bcc0dba/s/master "wercker status")](https://app.wercker.com/project/byKey/e2a879f4677e679c0bbf8fa82bcc0dba)
 [![Coverage status](https://coveralls.io/repos/oracle/opengrok/badge.svg?branch=master)](https://coveralls.io/r/oracle/opengrok?branch=master)
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