feat(error): add private __Nonexhaustive variant to Error
feat(error): add private __Nonexhaustive variant to Error

BREAKING CHANGE: Adds a new variant to public Error enum. The proper fix
  is to stop matching exhaustively on `hyper::Error`.

clatour/hyper,sfackler/hyper,lame-nickname/hyper,yazaddaruvala/hyper,Twey/hyper,hannobraun/hyper,fengsp/hyper,TimNN/hyper,golddranks/hyper,nickgonzales/hyper,erickt/hyper,bheesham/hyper,giftcards/hyper,tshepang/hyper,Twey/hyper,peterhj/hyper,markuskobler/hyper,tempbottle/hyper,markuskobler/hyper,hyperium/hyper,bonifaido/hyper,Twey/hyper,nickgonzales/hyper,golddranks/hyper,yazaddaruvala/hyper,mneumann/hyper,nickgonzales/hyper,rschulman/hyper,fhahn/hyper,hannobraun/hyper,hyperium/hyper,yangxingpping/hyper,Keats/hyper,pyfisch/hyper,jmmaranan/hyper,golddranks/hyper,markuskobler/hyper,reem/hyper,ianks/hyper,hannobraun/hyper,Keats/hyper,manuel-woelker/hyper,Keats/hyper,tshepang/hyper,tshepang/hyper,mitsuhiko/hyper,mfeckie/hyper,mre/hyper,achanda/hyper,fuchsnj/hyper,hyperium/hyper,steveklabnik/hyper,softprops/hyper,youprofit/hyper