Auto connect

[tiagolobocastro]

Use Case:

At the moment the library takes care of reconnections, but the it can't connect to the server to begin with it just fails. Might be nice to have the library handle the initial connection retries by itself, depending on an option in Options.

Proposed Change:

Add an option to auto connect to Options and in the client run set use_backoff accordingly in

nats.rs/src/asynk/client.rs

Line 352 in 15cde29

let mut use_backoff = false;

Who Benefits From The Change(s)?

No big deal, as we can always add a retry with timeout ourselves but it might avoid having to do it...

Alternative Approaches

User of the library adds it's own retry logic, should they wish to retry ofcourse.