prepare Basque translation to be enabled

customize.dist/messages.js

@@ -6,6 +6,7 @@ var map = {
     'de': 'Deutsch',
     'el': 'Ελληνικά',
     'es': 'Español',
+    //'eu': 'Euskara',
     'fi': 'Suomi',
     'fr': 'Français',
     //'hi': 'हिन्दी',

customize.dist/translations/messages.eu.js

@@ -0,0 +1,14 @@
+/*
+ * You can override the translation text using this file.
+ * The recommended method is to make a copy of this file (/customize.dist/translations/messages.{LANG}.js)
+   in a 'customize' directory (/customize/translations/messages.{LANG}.js).
+ * If you want to check all the existing translation keys, you can open the internal language file
+   but you should not change it directly (/common/translations/messages.{LANG}.js)
+*/
+define(['/common/translations/messages.eu.js'], function (Messages) {
+    // Replace the existing keys in your copied file here:
+    // Messages.button_newpad = "New Rich Text Document";
+
+    return Messages;
+});
+