fix(maintainer): fix missing maintainers

Closes #497
fix(package): detect package is private or not

Use `services/common.js` isPrivatePackage(name)
update private maintainer only
Merge pull request #498 from cnpm/fix-maintainers

fix(maintainer): fix missing maintainers
fix(sync): should not sync package when maintainers sort change

Closes #500
Merge pull request #501 from cnpm/sync-hotfix

fix(sync): should not sync package when maintainers sort change
Release 2.0.0-beta3
feat(middleware): block Ruby user-agent

Closes #502
Merge pull request #503 from cnpm/block-ruby

feat(middleware): block Ruby user-agent
Merge remote-tracking branch 'upstream/master'