Remove version number from query string

functions.php

<?php

/**
 * Remove the ver query argument from the source path
 * @param $src  Script loader source path.
 *
 * @return string
 */
function tm_remove_query_string_version( $src ){
	return remove_query_arg( 'ver', $src );
}
add_filter( 'script_loader_src', 'tm_remove_query_string_version' );
add_filter( 'style_loader_src', 'tm_remove_query_string_version' );