3.7.0

CHANGES:

• Drop unneeded mirage-protocols dependency (@hannesm, #537)
• Delete HTTP functor and use happy-eyeballs (@dinosaure, #539)
• Be compatible with mirage-protocols.7.0.0 (@dinosaure, #541)
• Use Lwt.pause instead of Lwt_unix.yield (@dinosaure, #542)
• Link with logs and logs.fmt (@MisterDA, #544)