this all looks good, but!
There is not even one possibility to translate your plugin.
No where in your code your are using __('my string', 'mypluginname') ,
This is a no go for many many people and nations.
How about updating your code and I make a German Translation?
load_plugin_textdomain( 'wordpress-seo', false, dirname( plugin_basename( __FILE__ ) ) . '/languages' );
__( 'Page %d of %d', 'wordpress-seo' )
Would be great,