Language names via intl library. Fixes #773

library/intl/src/Exception/UnknownLocaleException.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace CommerceGuys\Intl\Exception;
+
+/**
+ * This exception is thrown when an unknown locale is passed to a repository.
+ */
+class UnknownLocaleException extends InvalidArgumentException implements ExceptionInterface
+{
+}