Improve 2.0.0 changelog
Improve 2.0.0 changelog

ZalmanB/sinatra-activerecord,sdolmo/sinatra-activerecord,janko-m/sinatra-activerecord,avillanu/uberapp,exviva/sinatra-activerecord,BrunaNett/sinatra-activerecord,avillanu/uberapp,townie/sinatra-activerecord