Ensure that an error as a map is properly displayed
Ensure that an error as a map is properly displayed

Observed this when running a `doex ls`

```
** (Protocol.UndefinedError) protocol String.Chars not implemented for %{"id" => "Unauthorized", "message" => "Unable to authenticate you"} of type Map. This protocol is implemented for the following type(s): Float, DateTime, Time, List, Version.Requirement, Atom, Integer, Version, Date, BitString, NaiveDateTime, URI
    (elixir 1.11.2) lib/string/chars.ex:3: String.Chars.impl_for!/1
    (elixir 1.11.2) lib/string/chars.ex:22: String.Chars.to_string/1
    (doex 0.12.1) lib/doex/client.ex:139: Doex.Client.analyze_result/2
    (doex 0.12.1) lib/doex/client.ex:127: Doex.Client.list_droplets/0
    (doex 0.12.1) lib/doex/cli/ls.ex:37: Doex.Cli.Ls.run/1
    (elixir 1.11.2) lib/kernel/cli.ex:124: anonymous fn/3 in Kernel.CLI.exec_fun/2
```

capbash/doex