301 when using default endpoint

[Louis Pilfold]

iex(2)> Airbrakex.notify(%UndefinedFunctionError{reason: "test"})
{:ok,
 %HTTPoison.Response{body: "",
  headers: [{"Location",
    "https://airbrake.io/api/v3/projects/142622/notices?key=9ed9a66fa0482ea7155c89b1c5389
eda"},
   {"Content-Length", "0"}, {"Connection", "keep-alive"}], status_code: 301}}

Seems like we should be using https://airbrake.io now.

Also, the default of this lib is to use http, not https. This seems like a security risk