Refactored exceptions to properly use package exceptions

module/Rest/src/Exception/AuthenticationException.php

@@ -3,9 +3,7 @@ declare(strict_types=1);
 
 namespace Shlinkio\Shlink\Rest\Exception;
 
-use Shlinkio\Shlink\Common\Exception\ExceptionInterface;
-
-class AuthenticationException extends \RuntimeException implements ExceptionInterface
+class AuthenticationException extends RuntimeException
 {
     public static function fromCredentials($username, $password)
     {

module/Rest/src/Exception/ExceptionInterface.php

@@ -0,0 +1,8 @@
+<?php
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Rest\Exception;
+
+interface ExceptionInterface extends \Throwable
+{
+}

module/Rest/src/Exception/RuntimeException.php

@@ -0,0 +1,8 @@
+<?php
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Rest\Exception;
+
+class RuntimeException extends \RuntimeException implements ExceptionInterface
+{
+}