Fix for worker names that do not implement String.Chars

[philipgiuliani]

I got the following crash when adding another node to the cluster:

protocol String.Chars not implemented for {:livechat, "room_name"} of type Tuple. This protocol is implemented for the following type(s): Cldr.Calendar.Duration, Cldr.Unit, Money, Postgrex.Copy, Postgrex.Query, Decimal, URI, BitString, Float, NaiveDateTime, Date, DateTime, Version.Requirement, Version, Atom, List, Time, Integer