Update REF_09_models.go
Update REF_09_models.go

restored Alerts to use uppercase in code (Go struct property names and datastore field names) and lowercase in JSON
GoogleCloudPlatformTraining/cpd200-conference-central-go,GoogleCloudPlatformTraining/cpd200-conference-central-go,GoogleCloudPlatformTraining/cpd200-conference-central-go