HTTP Authorization header instead of custom header

Is there any reason you're using a `X-AUTHENTICATION-TOKEN` custom header instead of the standard HTTP `Authorization` header usually used for token (and basic, etc.) auth?

This also works well with Rails' [`ActionController::HttpAuthentication::Token`](http://api.rubyonrails.org/classes/ActionController/HttpAuthentication/Token.html) server-side which uses the Authorization header.