v0.15.0

Features

• Support page property on query (#45)
• Add getRecordByID method to database object (#22)
• Support user discovery with username (SkygearIO/skygear-server#90, #32)

Other Notes

• Fix error code list to match server side (#49)
• Add auto deploy example to https://sdkjsexample.skygeario.com/static/example/index.html (#15)
• Make the asset toJSON and fromJSON mirror on $url key (#10)