Laravel安装:即使php版本大于5，也找不到Pacakge

我已经使用这个composer create-project laravel/laravel --prefer-dist命令通过git安装了laravel框架。但是我会得到以下错误

Problem 1
    - laravel/framework v5.0.4 requires php >=5.4.0 -> no matching package found
Potential causes:
 - A typo in the package name
 - The package is not available in a stable-enough version according to your min
imum-stability setting

我的php版本是5.6.3，我提到了一些与我的问题有关的问题，但没有帮助我。

CMPOSER.JSON

{
    "name": "laravel/laravel",
    "description": "The Laravel Framework.",
    "keywords": ["framework", "laravel"],
    "license": "MIT",
    "type": "project",
    "require": {
        "laravel/framework": "5.0.*"
    },
    "require-dev": {
        "phpunit/phpunit": "~4.0",
        "phpspec/phpspec": "~2.1"
    },
    "autoload": {
        "classmap": [
            "database"
        ],
        "psr-4": {
            "App''": "app/"
        }
    },
    "autoload-dev": {
        "classmap": [
            "tests/TestCase.php"
        ]
    },
    "scripts": {
        "post-install-cmd": [
            "php artisan clear-compiled",
            "php artisan optimize"
        ],
        "post-update-cmd": [
            "php artisan clear-compiled",
            "php artisan optimize"
        ],
        "post-create-project-cmd": [
            "php -r '"copy('.env.example', '.env');'"",
            "php artisan key:generate"
        ]
    },
    "config": {
        "preferred-install": "dist"
    }
}