Fixed failing unit test - added ability to unset config

Author: mapril

lib/SparkPost/SparkPost.php

@@ -51,6 +51,10 @@ public static function getConfig() {
 		}
 		return self::$config;
 	}
+	
+	public static function unsetConfig() {
+		self::$config = NULL;
+	}
 }
 
 ?>

test/unit/SparkPostTest.php

@@ -20,6 +20,7 @@ public function testConstructorCannotBeCalled() {
 	 * @expectedExceptionMessage No configuration has been provided
 	 */
 	public function testGetConfigEmptyException() {
+		SparkPost::unsetConfig();
 		SparkPost::getConfig();
 	}