Adding SyncCenter
Merge branch 'master' of https://github.com/CMUPracticum/TrailScribe
Adding SyncCenter
Adding sync center
Merge branch 'sync'
Adding sync logic to backend to retrieve maps
Merge branch 'master' of https://github.com/CMUPracticum/TrailScribe
Adding sync logic
Created model and DAO for Sample
Merge branch 'master' of https://github.com/CMUPracticum/TrailScribe
Fix: handled exception when get null sync result
Merge remote-tracking branch 'cmu/master'