Encoding int32, int64 to signed varint?

[Thunnini]

package main

import (
	"encoding/hex"
	"fmt"

	amino "github.com/tendermint/go-amino"
)

type TestBin struct {
	A int64 `binary:"fixed64"`
}

type TestBin2 struct {
	A int64
}

func main() {
	cdc := amino.NewCodec()

	bz, err := cdc.MarshalBinary(TestBin{1})
	if err != nil {
		panic(err)
	}
	fmt.Println(hex.EncodeToString(bz))

	bz, err = cdc.MarshalBinary(TestBin2{1})
	if err != nil {
		panic(err)
	}
	fmt.Println(hex.EncodeToString(bz))
}

Result is

09090100000000000000
020802

https://github.com/tendermint/go-amino/blob/master/codec.go#L521
https://github.com/tendermint/go-amino/blob/master/binary-encode.go#L89

In go-amino, it seemed that they encode int32, 64 to fixed length when users define variables with fixed option.
But js-amino encode int32, 64 to fixed length by default.
I think it is better to encode int32, 64 to varint by default, and support options that encode int32, 64 to fixed length.

[TanNgocDo]

Thanks @Thunnini , options is the target I will implement. I'm trying to fix your last issues. Stay tune for more update :)

[Thunnini]

@TanNgocDo, I really appreciate your efforts. This project is helping me a lot. :)

[TanNgocDo]

Could you please check new commit: f918a9b ?