taskman_deps/deps.inc.php

<?php
namespace taskman;

task('deps_update', function()
{
  update_composer(true);
});

//NOTE: COMPOSER_FORCE_UPDATE = true will make composer to update packages and
//      a lock file
//      COMPOSER_FORCE_UPDATE = false will make composer install dependencies 
//      listed in a lock file in case if it's present
function update_composer($COMPOSER_FORCE_UPDATE = false)
{
  global $GAME_ROOT;
  include("$GAME_ROOT/composer/update.php");
}