Fix proc_lib example code

Thanks to Marc Campbell for the heads up!
Merge branch 'fix-server-racecon' of git://github.com/fishcakez/ranch
Update AUTHORS file
Update Ranch to 0.8.0
Allow handshaking outside of an acceptor

A transport's accept/2 can now also return
{ok, Socket, fun((timeout()) -> ok | {error, term()}). The fun will be
called inside ranch:accept_ack/2 to finish handshaking. The new,
optional second argument to ranch:accept_ack/2 is passed to the fun
returned by an accept/2 as the timeout for handshaking.