func (s *RepositoriesService) ListKeys(ctx context.Context, owner string, repo string, opts *ListOptions) ([]*Key, *Response, error) {
	u := fmt.Sprintf("repos/%v/%v/keys", owner, repo)
	u, err := addOptions(u, opts)
	if err != nil {
		return nil, nil, err
	}
	req, err := s.client.NewRequest("GET", u, nil)
	if err != nil {
		return nil, nil, err
	}
	var keys []*Key
	resp, err := s.client.Do(ctx, req, &keys)
	if err != nil {
		return nil, resp, err
	}
	return keys, resp, nil
}
The Key type is defined in users_keys.go
ListKeys lists the deploy keys for a repository.

GitHub API docs: https://developer.github.com/v3/repos/keys/#list
package github
import (
	"context"
	"fmt"
)