Laravel 5.6 + cPanel + Composer Error: Using wrong PHP Even though 7.2 is installed

I am trying to install Laravel 5.6 on a cPanel sandbox and I am getting strange behavior where composer is trying to use PHP 5.6 even though 7.2 is setup. Here are the details:

# composer --version
Composer version 1.1.1 2016-05-17 12:25:44

The command which php returns nothing. But when I do alias I get the following:

alias php='/usr/local/bin/ea-php72'

And if I run php -v I see

# php -v
PHP 7.2.4 (cli) (built: Apr  4 2018 00:56:46) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies

I am going to assume that it’s working. As you can tell, I have very little experience running Laravel on cPanel, but I digress.

Here’s the error:

# composer update
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
    - This package requires php ^7.1.3 but your PHP version (5.6.35) does not satisfy that requirement.
  Problem 2
    - laravel/framework v5.6.9 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.8 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.7 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.6 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.5 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.4 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.3 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.2 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.15 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.14 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.13 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.12 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.11 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.10 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.1 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.0 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework 5.6.x-dev requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - laravel/framework v5.6.15 requires php ^7.1.3 -> your PHP version (5.6.35) does not satisfy that requirement.
    - Installation request for laravel/framework 5.6.* -> satisfiable by laravel/framework[5.6.x-dev, v5.6.0, v5.6.1, v5.6.10, v5.6.11, v5.6.12, v5.6.13, v5.6.14, v5.6.15, v5.6.2, v5.6.3, v5.6.4, v5.6.5, v5.6.6, v5.6.7, v5.6.8, v5.6.9].

Now, I did find a thread that says to add a platform to the composer.json:

"platform": {
    "php": "7.1.3"
}

This did let me install my vendor packages, but it’s obviously not meant to be a solution since you are simply faking the platform (I think). When it comes time to really use php7 I get the following error on null coalescing operator, which is a php 7 feature, and so it’s still trying to use php5.6.

> IlluminateFoundationComposerScripts::postAutoloadDump

Parse error: syntax error, unexpected '?' in /public_html/vendor/laravel/framework/src/Illuminate/Foundation/helpers.php on line 233

Additional notes:

phpinfo() - PHP Version 7.2.4
php.ini - /opt/cpanel/ea-php72/root/etc
core PHP Version 7.2.4

# /usr/bin/env php -v
ea-php-cli Copyright 2017 cPanel, Inc.
PHP 5.6.35 (cli) (built: Apr  4 2018 00:55:31)
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies

My required composer.json is as follows:

"require": {
    "php": "^7.1.3",
    "edujugon/laravel-google-ads": "^1.4",
    "fideloper/proxy": "^4.0",
    "laravel/framework": "5.6.*",
    "laravel/tinker": "^1.0"
}

Any ideas on how I can fix this?