Fix ruby syntax in readme.
Fix ruby syntax in readme.

adamjmcgrath/SimpleAuth-1,tofaruk/SimpleAuth-1,jiakai-lian/SimpleAuth,tipbit/SimpleAuth,AlexanderMazaletskiy/SimpleAuth,martinpilch/SimpleAuth,machelix/SimpleAuth,calebd/SimpleAuth,hyperspacemark/SimpleAuth,sburavtsov/SimpleAuth,hoanganh6491/SimpleAuth