func (s *AppsService) ListRepos(ctx context.Context, opts *ListOptions) ([]*Repository, *Response, error) {
	u, err := addOptions("installation/repositories", opts)
	if err != nil {
		return nil, nil, err
	}
	req, err := s.client.NewRequest("GET", u, nil)
	if err != nil {
		return nil, nil, err
	}
	req.Header.Set("Accept", mediaTypeIntegrationPreview)
	var r struct {
		Repositories []*Repository `json:"repositories"`
	}
	resp, err := s.client.Do(ctx, req, &r)
	if err != nil {
		return nil, resp, err
	}
	return r.Repositories, resp, nil
}
ListRepos lists the repositories that are accessible to the authenticated installation.

GitHub API docs: https://developer.github.com/v3/apps/installations/#list-repositories
package github
import (
	"context"
	"fmt"
)