Make all provider headers private.
Make all provider headers private.

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