Offline signer

[peterbroadhurst]

Create a simple command-line to sign and submit a transaction, without needing to run the server and make a HTTP call.

Example that works for a ff created example Eth network running on http://localhost:5100:

go run ./ffsigner/main.go send-transaction -f ./test/offline-signer.conf.yaml -i ./test/offline-tx.json

[awrichar]

I gave this a try and it seems to work great.