Adding the classes for the emergency_message table and the emergency_alert_log table
The emergency message table will hold generic and specific messages for emergencies
	- there is a user_id field if a user wants to create his own messages
	- there is a emergency_type_id field to associate messages to types if you want
The emergency_alert_log table keeps track oh which messages were sent for which emergencies
	- Think of it as a table that keeps the history of alerts for an emergency