Fixed test, and add default value for new config minimumLevel

Author: Jozhef

src/Defaults.php

@@ -1,6 +1,6 @@
 <?php namespace Rollbar;
 
-use Rollbar\Utilities;
+use Monolog\Logger;
 use Rollbar\Payload\Notifier;
 use Psr\Log\LogLevel;
 
@@ -313,6 +313,11 @@ public function maxItems($value = null)
         return $value !== null ? $value : $this->maxItems;
     }
 
+    public function minimumLevel($value = null)
+    {
+        return $value !== null ? $value : $this->minimumLevel;
+    }
+
     private $psrLevels;
     private $errorLevels;
     private $autodetectBranch = false;
@@ -358,4 +363,5 @@ public function maxItems($value = null)
     private $scrubFields;
     private $customTruncation = null;
     private $maxItems = 10;
+    private $minimumLevel = Logger::ERROR;
 }