Use Go modules

[slai]

This supercedes #11 by using the new Go modules system instead.

[oliland]

📦

[msf]

This is great, what instructions did you follow ?
We should do this on goland... but that's a much bigger task...

[slai]

I didn't write down the exact commands, but roughly it went -

# generate the gopkg.lock files (these aren't used later as they're part of dep)
dep init
# generate go.mod from gopkg.lock
go mod init <package name>
# can now delete the files created by dep

It's actually really simple. The annoying part is probably tweaking the version data to match what we had vendored.

[slai]

Turns out go mod can also infer dependencies, so all that's necessary is -

go mod init <package name>
go build