Update async-http-client to 2.6.0
Update async-http-client to 2.6.0

http4s/http4s,rossabaker/http4s,aeons/http4s,ChristopherDavenport/http4s,rossabaker/http4s,aeons/http4s,ChristopherDavenport/http4s,ChristopherDavenport/http4s,aeons/http4s