This change has no functional changes, it only removes dead code.
Go 1.4+ has https://golang.org/pkg/net/http/#Request.BasicAuth method for http.Request and it was requested by CoreOS(kelsey) [1] with the same functionalities. If dex's Go development is being done in Go 1.4 or later, we should use the standard library. Thanks! --- [1] https://codereview.appspot.com/76540043/