composer安裝laravel安裝不上
什麼情況：
D:\myphp_www\PHPTutorial\WWW\PHPDemo\laravel>composer create-project laravel/laravel Laravel --prefer-dist "5.5.*"
[ InvalidArgumentException]
在可使用PHP 版本5.4.45 安裝的版本中找不到版本5.5.* 的包laravel/laravel。
##create-project [-s|--stability STABILITY] [--prefer-source] [--prefer-dist] [--repository REPOSITORY] [--repository-url REPOSITORY
#-URL] [--dev] [--no-dev] [--no-custom-installers] [--no-scripts] [--no-progress] [--no-secure-http ] [- -keep-vcs] [--remove-vcs] [-
-no-install] [--ignore-platform-reqs] [--] [
