I want to release 2.0 in September. At the moment there is no open issues or anything stopping us. We just need to wait for a final release of PSR-18. @joelwurtz made [a comment](https://github.com/php-http/httplug/pull/128/files/cbc903aadbe53e2dd39ebc700e6a5aea00b2bc46#r204876337) about async. Is that something we should do before 2.0?