a little copying is better than a little dependency
-- go proverb
We have this dependency on docker, a.k.a moby: a gigantic library, and we only need ~70 LOC,
so here I tried moving it inline instead.
Co-authored-by: Felix Lange <fjl@twurst.com>
This commit:
- Adds a --msgfile option to read the message to sign from a file
instead of command line argument.
- Adds a unit test for signing subcommands.
- Removes some weird whitespace in the code.
