Released reactphp/http v1.8.0

[clue]

Released reactphp/http v1.8.0 today 🎉

• Feature: Support for default request headers.
  (#461 by @51imyy)

  $browser = new React\Http\Browser();
  $browser = $browser->withHeader('User-Agent', 'ACME');
  
  $browser->get($url)->then(…);

• Feature: Forward compatibility with upcoming Promise v3.
  (#460 by @clue)

– See https://github.com/reactphp/http/releases/tag/v1.8.0