由于系统PHP版本而安装Laravel / Spark的问题

我正在使用新的开发机器，我在安装Laravel，Spark或者任何需要比PHP 5.5.30更新的东西时遇到问题 .

问题是，我还尝试使用本教程将我的系统PHP版本更新为PHP 7：https://coolestguidesontheplanet.com/upgrade-php-on-osx/

☁  /webroot  spark new app
Crafting application...
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

Problem 1
 - This package requires php >=5.6.4 but your PHP version (5.5.30) does not satisfy that requirement.
Problem 2
    - Installation request for laravel/framework v5.3.20 -> satisfiable by laravel/framework[v5.3.20].
    - laravel/framework v5.3.20 requires php >=5.6.4 -> your PHP version (5.5.30) does not satisfy that requirement.
Problem 3
    - Installation request for phpunit/php-code-coverage 4.0.1 -> satisfiable by phpunit/php-code-coverage[4.0.1].
    - phpunit/php-code-coverage 4.0.1 requires php ^5.6 || ^7.0 -> your PHP version (5.5.30) does not satisfy that requirement.
Problem 4
    - Installation request for phpunit/phpunit 5.6.2 -> satisfiable by phpunit/phpunit[5.6.2].
 - phpunit/phpunit 5.6.2 requires php ^5.6 || ^7.0 -> your PHP version (5.5.30) does not satisfy that requirement.
Problem 5
    - Installation request for phpunit/phpunit-mock-objects 3.4.0 -> satisfiable by phpunit/phpunit-mock-objects[3.4.0].
    - phpunit/phpunit-mock-objects 3.4.0 requires php ^5.6 || ^7.0 -> your PHP version (5.5.30) does not satisfy that requirement.
Problem 6
    - Installation request for sebastian/code-unit-reverse-lookup 1.0.0 -> satisfiable by sebastian/code-unit-reverse-lookup[1.0.0].
 - sebastian/code-unit-reverse-lookup 1.0.0 requires php >=5.6 -> your PHP version (5.5.30) does not satisfy that requirement.
Problem 7
    - Installation request for sebastian/object-enumerator 1.0.0 -> satisfiable by sebastian/object-enumerator[1.0.0].
 - sebastian/object-enumerator 1.0.0 requires php >=5.6 -> your PHP version (5.5.30) does not satisfy that requirement.
Problem 8
    - Installation request for sebastian/resource-operations 1.0.0 -> satisfiable by sebastian/resource-operations[1.0.0].
 - sebastian/resource-operations 1.0.0 requires php >=5.6.0 -> your PHP version (5.5.30) does not satisfy that requirement.
Problem 9
    - Installation request for sebastian/version 2.0.0 -> satisfiable by sebastian/version[2.0.0].
    - sebastian/version 2.0.0 requires php >=5.6 -> your PHP version (5.5.30) does not satisfy that requirement.

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Downloading Spark...

我不想通过在编辑器文件中编辑来绕过所需的PHP版本，因为我不确定它是否在安装应用程序时导致问题 . 我的Spark或Laravel安装都没有工作，它们只是给出500状态错误，它可能是其他东西，但我假设它是同样的问题 .