Update README.md (#4911)
Update README.md (#4911)

update links to rubydoc.info to the url `www.rubydoc.info` since the ssl certificate is only valid for www.rubydoc.info (not rubydoc.info)
plataformatec/devise,Qwiklabs/devise,rubyrider/devise,Qwiklabs/devise,rubyrider/devise,plataformatec/devise,rubyrider/devise