安装一个软件包，而无需与作曲家检查所有要求

我有一个像这样的composer.json：

{
"require": {
    "symfony/yaml" : "dev-master",
    "symfony/console" : "dev-master",
    "ebuildy/ebuildy" : "dev-master",
    "keboola/php-encryption": "dev-master",
    "pear-pear.php.net/mail_mime" : "*",
    "pear-pear.php.net/http_request2" : "*",
    "pear-pear.php.net/mail_mimedecode" : "*",
    "microsoft/windowsazure": "*",
    "rollbar/rollbar": "dev-master",
    "facebook/php-sdk-v4" : "4.0.*",
    "happyr/linkedin-api-client": "dev-master",
    "zircote/swagger-php" : "dev-master",
    "google/apiclient" : "dev-master"
},
    "autoload": {
        "psr-0": {
           "bizlunch": "src/"
        }
    },
    "minimum-stability": "dev"
}

刚刚添加了"google/apiclient"，我想在不检查其他软件包要求的情况下安装这个新软件包（因为在我的开发机器上，"keboola/php-encryption"抱怨crypt ext丢失和其他东西）。

正确的命令是什么？已尝试更新软件包，但失败：

$root: php composer.phar update google/apiclient       
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.
  Problem 1
- keboola/php-encryption dev-master requires ext-mcrypt * -> the requested PHP extension mcrypt is missing from your system.