title: Connection pool is not initialized in unit test with scalikejdbc 2.4.1
body: <p>I have a problem when running unit test using specs2with scalikejdbc 2.4.1, scalikejdbc-config2.4.1
  Here is my code:</p>
  
  <pre><code>    object PostDAOImplSpec extends Specification{
  
    sequential
  
    DBs.setupAll
    implicit val session = AutoSession
  
    "resolveAll shoudn't have any syntax error" in new AutoRollback {
  
      val postIds = DB readOnly { implicit session =&gt;
        sql"select post_id from posts".map(_.long(1)).list.apply()
      }
  
    }
  
    DBs.closeAll()
  
  }
  </code></pre>
  
  <p>Here is logs:</p>
  
  <pre><code>    09:11:16.931 [main] DEBUG scalikejdbc.ConnectionPool$ - Registered connection pool : ConnectionPool(url:jdbc:mysql://localhost/bbs, user:root) using factory : &lt;default&gt;
  09:11:17.130 [main] DEBUG scalikejdbc.ConnectionPool$ - Registered connection pool : ConnectionPool(url:jdbc:mysql://localhost/bbs, user:root) using factory : &lt;default&gt;
  
  java.lang.IllegalStateException: Connection pool is not yet initialized.(name:'default)
  java.lang.IllegalStateException: Connection pool is not yet initialized.(name:'default)
  </code></pre>
  
  <p>As you can see from the first two of lines, scalikejdbc found database's configuration, but it can't initilize connection pool.
  Do you have any idea? Thanks.</p>