cmd/go2avro: when it's run it modifies go.mod and go.sum

[sixstone-qq]

Following these commands:

cd heetch/avro
go build ./cmd/go2avro/.
./go2avro Type

It modifies the go.sum and go.mod as a side-effect.

This issue is intended to fix this side-effect.

[sneko]

Hi @sixstone-qq ,

It would be cool if we could install globally "go2avro" into the $GOPATH/bin without dealing with the build.

Would be easier to try it out.

[sneko]

Oh sorry, my mistake!

By doing

go get github.com/heetch/avro/cmd/go2avro/...

It works well.

Maybe this could be added to the documentation?