createDummyProduct should use the $currency_code parameter

<?php
  public function createDummyProduct($sku = '', $title = '', $amount = -1, $currency_code = 'USD', $uid = 1, $type_given = 'product') {
    $new_product->commerce_price[LANGUAGE_NONE][0]['amount'] = ($amount < 0) ? rand(2, 500) : $amount;
    $new_product->commerce_price[LANGUAGE_NONE][0]['currency_code'] = 'USD';
  }
?>

As shown in the cut down version of createDummyProduct(), the currency is hard coded to USD rather than using the $current_code parameter.