- use elliptic.MarshalCompressed
- use elliptic.UnmarshalCompressed
- for older go versions use old methods
- update dependencies
- github.com/mr-tron/base58 v1.2.0
- github.com/pkg/errors v0.9.1
- github.com/stretchr/testify v1.7.0
Signed-off-by: Evgeniy Kulikov <kim@nspcc.ru>