Test support for 4.1 -> Some issues found

[marxjohnson]

I have tested installation, automated tests, and basic indexing/searching on Moodle 4.1. I found the following minor issues:

• Unit tests need renaming and namespacing to match current conventions.
• Some tests use assertions which are deprecated in newer versions of PHPUnit.
• Tests for proxy configuration fail if a proxy is configured for the development environment.

[dmitriim]

hey! @marxjohnson have you seen something like following error while working on the plugin for 4.1?

1) search_elastic_esrequest_testcase::test_get
Error: Class 'GuzzleHttp\Middleware' not found

/var/www/catalyst-moodle/search/engine/elastic/tests/esrequest_test.php:60
/var/www/catalyst-moodle/lib/phpunit/classes/advanced_testcase.php:80
phpvfscomposer:///var/www/catalyst-moodle/vendor/phpunit/phpunit/phpunit:97

getting this in our CI for 4.1 upstream branch...

[dmitriim]

By the way the error is gone on the branch from #90

[marxjohnson]

Yes, I saw that in a few places during my 4.1 testing. I think it's to do with the namespacing (or lack of) in test classes meaning it's not finding the Guzzle class, so I think my changes fixed that.