Avoids the really sloppy flag passing to `open_pikerd()` and allows for
separation of the individual docker daemon starts.
Also add a new `root_conf() -> Path` fixture which will open and load
the `dict` for the new root `conf.toml` file.
Due to making ahabd supervisor init more async we need to be more
tolerant to mkts server startup: the grpc machinery needs to be up
otherwise a client which connects to early may just hang on requests..
Add a reconnect loop (which might end up getting factored into client
code too) so that we only block on requests once we know the client
connection is actually responsive.
Tyler Goodlet
Esmeralda Gallardo
Guillermo Rodriguez