Support Bitcoin Core cookie file

[lukechilds]

Currently to authenticate we need to do:

DAEMON_URL=http://username:password@hostname:port

It would be great if the credentials were optional and we could instead specify the Bitcoin Core cooke path:

DAEMON_URL=http://hostname:port
DAEMON_COOKIE_FILE=$HOME/.bitcoin/.cookie

[n1rna]

I would like to take on this one.

[drizzt]

As workaround you can do that:

DAEMON_URL="http://$(cat "$HOME/.bitcoin/.cookie")@hostname:port"

if you use bash