Test suite: Add $this->factory->attachment->create( $file, $parent = 0, $args = array() ), which wraps wp_insert_attachment().

In the future, we may want an upload() method that wraps (and fakes) media_handle_upload(), to populate metadata.



git-svn-id: https://unit-tests.svn.wordpress.org/trunk@1241 4a5a2adb-35eb-4268-9a1b-fe04a4134342