Issue #2350917 by alexpott: Update Symfony YAML library to support whole number floats.

composer.json

composer.lock

core/vendor/composer/installed.json

core/vendor/symfony/yaml/Symfony/Component/Yaml/Inline.php

core/vendor/symfony/yaml/Symfony/Component/Yaml/Parser.php

core/vendor/symfony/yaml/Symfony/Component/Yaml/README.md

.../symfony/yaml/Symfony/Component/Yaml/Tests/DumperTest.php

...omponent/Yaml/Tests/Fixtures/YtsSpecificationExamples.yml

.../symfony/yaml/Symfony/Component/Yaml/Tests/InlineTest.php

.../vendor/symfony/yaml/Symfony/Component/Yaml/composer.json