Merge pull request thephpleague#274 from thephpleague/feat-deprecated

Fix deprecated issues

docs: improve README.md (thephpleague#265)

Co-authored-by: Christopher Georg <christopher.georg@sr-travel.de>

require php-http/message-factory directly (thephpleague#261)

This library still uses the deprecated php-http message factories. They have been deprecated since a while in favor of PSR-17 message factories.

php-http/discovery no longer automatically installs php-http/message-factory.

Allow Symfony 6 (thephpleague#254)

Update composer.json

Update composer.json

Create FUNDING.yml

Merge pull request thephpleague#225 from KenorFR/KenorFR-deprecated-s…

…ymfony

corrects deprecated symfony 5.1

Merge pull request thephpleague#221 from thephpleague/feat-testactual…

…request

Test actual request instead of mock

Update .travis.yml