Fix cosmetic issues and update api documentation

app/Model/Board.php

@@ -2,8 +2,6 @@
 
 namespace Kanboard\Model;
 
-use PicoDb\Database;
-
 /**
  * Board model
  *

app/Model/LastLogin.php

@@ -65,9 +65,9 @@ class LastLogin extends Base
 
         if (count($connections) >= self::NB_LOGINS) {
             $this->db->table(self::TABLE)
-                     ->eq('user_id', $user_id)
-                     ->notin('id', array_slice($connections, 0, self::NB_LOGINS - 1))
-                     ->remove();
+                ->eq('user_id', $user_id)
+                ->notin('id', array_slice($connections, 0, self::NB_LOGINS - 1))
+                ->remove();
         }
     }
 

app/Model/User.php

@@ -137,7 +137,7 @@ class User extends Base
      *
      * @access public
      * @param  string  $username  Username
-     * @return array
+     * @return integer
      */
     public function getIdByUsername($username)
     {