update podspec to 5.0.1

podspec 5.0.0 release

Merge branch 'dev_for_swift5.0' of https://github.com/alibaba/HandyJSON…

… into dev_for_swift5.0

update .swift-version

update podspec & release 4.2.1

update readme

(podspec) update version

(podspec) update version

(release) version 4.1.1