[skip ci] fix travis badge url

README.md

@@ -5,7 +5,7 @@ to provide a more traditional way to perform logging in an erlang application
 that plays nicely with traditional UNIX logging tools like logrotate and
 syslog.
 
-[Travis-CI](http://travis-ci.org/erlang-lager/lager) :: ![Travis-CI](https://secure.travis-ci.org/erlang-lager/lager.png)
+[Travis-CI](http://travis-ci.org/erlang-lager/lager) :: [![Travis-CI](https://travis-ci.org/erlang-lager/lager.svg?branch=master)](http://travis-ci.org/erlang-lager/lager)
 
 Features
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