Error messages with invalid tokens

[HaleTom]

When the token is nil, I see:

** (Mix) Could not start application app: App.Application.start(:normal, []) returned an error: shutdown: failed to start child: App.Telegram
    ** (EXIT) an exception was raised:
        ** (ArgumentError) argument error
            :erlang.bit_size(nil)
            (nadia 0.7.0) lib/nadia/api.ex:9: Nadia.API.build_url/1
            (nadia 0.7.0) lib/nadia/api.ex:118: Nadia.API.request/3
            (app 0.1.1) lib/app/telegram/telegram.ex:46: App.Telegram.init/1
            (stdlib 3.14.1) gen_server.erl:417: :gen_server.init_it/2
            (stdlib 3.14.1) gen_server.erl:385: :gen_server.init_it/6
            (stdlib 3.14.1) proc_lib.erl:226: :proc_lib.init_p_do_apply/3

When it is an invalid, non-nil, I see:

[error] Telegram bot failed to self-identify{:error, %Nadia.Model.Error{reason: "Not Found"}}
** (Mix) Could not start application app: App.Application.start(:normal, []) returned an error: shutdown: failed to start child: App.Telegram

Could these errors be improved?