func (s *DefaultService) Signup(ctx context.Context, user, pass string) (err error) {
	return s.repo.Create(ctx, user, pass)
}
Signup creates a user with the given pass.
The user still needs to login.
package auth
import (
	"context"
	"errors"
)
type Service interface {
	Signup(ctx context.Context, user, pass string) error
	Login(ctx context.Context, user, pass string) (token string, err error)
	Logout(ctx context.Context, user, token string) error
	Validate(ctx context.Context, user, token string) error
}
var ErrBadAuth = errors.New("bad auth")
type DefaultService struct {
	repo Repository
}
func NewDefaultService(repo Repository) *DefaultService {
	return &DefaultService{
		repo: repo,
	}
}