Throw error when provider not supported
Throw error when provider not supported

DonSchenck/pkgcloud,apla/pkgcloud,pkgcloud/pkgcloud,temka1234/pkgcloud,songanbui/pkgcloud,Hopebaytech/pkgcloud,hacor/pkgcloud,Phanatic/pkgcloud,andrewsomething/pkgcloud,Phanatic/pkgcloud,bunglestink/pkgcloud,mdsummers/pkgcloud,mcanthony/pkgcloud,dionjwa/pkgcloud