title: how to configure slf4j on boneCP
body: <p>BoneCP version=0.7.1</p>
  
  <p>slf4j=1.7.5</p>
  
  <p>Every time when I connect to mysql. It would say</p>
  
  <pre><code>log4j:WARN No appenders could be found for logger (com.jolbox.bonecp.BoneCPConfig).
  log4j:WARN Please initialize the log4j system properly.
  log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
  </code></pre>
  
  <p>But I cann't find any configure Example with boneCP, just give me a example, with explain is good!</p>