Make local prefer lowest checking easier.

CONTRIBUTING.md

@@ -55,7 +55,7 @@ Great, so you want to contribute. Let's get started:
 1. Run the unit tests locally to ensure they pass:
 
     ```
-    php vendor/bin/phpunit --config phpunit.xml
+    vendor/bin/phpunit
     ```
 
 1. Write the code and unit tests for your bug fix or feature.
@@ -92,4 +92,4 @@ install [docker-compose](https://docs.docker.com/compose/) for your platform.
 ## Documentation
 
 The Phinx documentation is stored in the **docs** directory using the [RestructedText](https://docutils.sourceforge.io/rst.html)
-format. All documentation merged to `master` is automatically published to the Phinx documentation site available at https://docs.phinx.org.
+format. All documentation merged to main branch is automatically published to the Phinx documentation site available at https://docs.phinx.org.

composer.json

@@ -74,6 +74,8 @@
         "cs-fix": "phpcbf",
         "stan": "phpstan analyse",
         "stan-setup": "cp composer.json composer.backup && composer require --dev phpstan/phpstan:~1.9.0 && mv composer.backup composer.json",
+        "lowest": "validate-prefer-lowest",
+        "lowest-setup": "composer update --prefer-lowest --prefer-stable --prefer-dist --no-interaction && cp composer.json composer.backup && composer require --dev dereuromark/composer-prefer-lowest && mv composer.backup composer.json",
         "test": "phpunit --colors=always"
     },
     "bin": [