[misc] Allow passing credentials to use to create an extension

xwiki-platform-core/xwiki-platform-repository/xwiki-platform-repository-test/xwiki-platform-repository-test-utils/src/main/java/org/xwiki/repository/test/RepositoryTestUtils.java

@@ -93,6 +93,11 @@ public void deleteExtension(Extension extension)
     }
 
     public void addExtension(Extension extension) throws Exception
+    {
+        addExtension(extension, null);
+    }
+
+    public void addExtension(Extension extension, UsernamePasswordCredentials credentials) throws Exception
     {
         this.testUtils.deletePage("Extension", getPageName(extension));
 
@@ -129,7 +134,7 @@ public void addExtension(Extension extension) throws Exception
         addDependencies(extension);
 
         // Attach the file
-        attachFile(extension);
+        attachFile(extension, credentials);
     }
 
     public void addVersionObject(Extension extension)