Payment: cast Amount as Currency (#245)

fixes #244

feat: silverstripe 5 support

Update PHPUnit to 9.5 (#241)

* Added Github Actions Workflows

php-http/discovery required for 7.4 tests

* Updated composer.json

Upgraded PHPUnit to 9.5 and to php-http/guzzle7-adapter

* PHPUnit: Added void return type

setUp function

* PHPUnit: Added @doesNotPerformAssertions

For incomplete tests

* PHPUnit: Updated phpunit.xml.dist

Wrapped testsuite in testsuites

* PHPUnit: Added additional void return type

To tearDown, setUpBeforeClass and tearDownAfterClass functions

* PHPUnit: updated PaymentTest.php

Upgraded to php-http/guzzle7-adapter

* PHPUnit: updated PaymentMathTest.php

Reduced decimal places due to the limitation of using the number_format function

* PHP8.1 Compatibility

As per PR #239

* PHPUnit: added guzzlehttp/psr7 to composer.json

As a dev dependency

* PHPUnit: added expectException function

To all functions that expect failure

* PHPUnit: updated various as highlighted by GitHub Actions

- Changed a payment gateway url to sec.windcave.com for Payment Express tests.  Updated the version of omnipay/paymentexpress in composer.json to account for a recent branding change.
- Changed assertInternalType('array', etc.) to assertIsArray
- For Guzzlehttp\Psr7, replaced parse_response with Message::parseResponse
- Replaced contains function with a callback in BasePurchaseServiceTest.php
- Updated PaymentMathTest.php because the function bcsub cannot have a precision below 0
- Replaced strftime in Payment.php with date_format.  Added SilverStripe\Omnipay\Model\Payment\TitleTemplateDateFormat to the language files.  Removed unnecessary tests in PaymentModelTest.php because language settings cannot be dynamically changed.
- Added symfony/http-foundation as a dev dependency to composer.json
- Added php_codesniffer to ci.yml to ensure it is loaded
- Updated phpcs.xml.dist to align with the one used by SilverStripe Framework

* Updated various with PHP_CodeSniffer

Code beautifier & fixer

* Dropped travis

Replaced by GitHub Actions

[CVE-2022-29254] Add extra validation on payment completion

[CVE-2022-29254] Add extra validation on payment completion

[CVE-2022-29254] Add extra validation on payment completion

Merge pull request #2 from silverstripe-security/payment-completion-2

[CVE-2022-29254] Add extra validation on payment completion

Merge pull request #234 from tom890180/master

Anonymous recursive function requires use () to work & changed var passed into it to avoid infinite loop

Merge pull request #232 from bigfork/silent-exceptions

Fix issue where exceptions triggered by extensions could be silently swallowed

Add missing import statement