Fix ListBucket in s3bolt backend to honor page.Marker and page.MaxKeys#114

Aliexe-code wants to merge 2 commits intojohannesboyne:masterjohannesboyne/gofakes3:masterfrom

Aliexe-code:fix/issue-66-s3bolt-markerAliexe-code/gofakes3:fix/issue-66-s3bolt-markerCopy head branch name to clipboard