protected static function hasStaleCacheFile()
    {
        $composerTravisLintCache = getcwd()
            . DIRECTORY_SEPARATOR
            . self::CTL_CACHE;

        $travisConfiguration = getcwd()
            . DIRECTORY_SEPARATOR
            . self::TRAVIS_CONFIGURATION;

        if (file_exists($composerTravisLintCache) && file_exists($travisConfiguration)) {
            $travisConfigurationContent = trim(file_get_contents($travisConfiguration));
            $composerTravisLintCacheContent = trim(file_get_contents($composerTravisLintCache));

            if (md5($travisConfigurationContent) === $composerTravisLintCacheContent) {
                return false;
            }
        }

        return true;
    }