Implement order log (repository layer)

[aldy505]

The database should be SQLite3, and you should use event sourcing.
It would be nice if unit tests are included.

mock-shipping-provider/repository/order_log.go

Lines 10 to 20 in 68058d6

	type OrderLogRepository interface {
	// Create will insert multiple row into the database.
	// Because we are a mock server, nothing should be done through any
	// administrator dashboard or some sort that enable real people to
	// change the shipping status. Future events can be inserted here.
	Create(ctx context.Context, logEntry LogEntry) error
	// Get will return only the order history that are before or equal to
	// current time. If there are any order history which event happen
	// after current time, it will not be shown.
	Get(ctx context.Context, referenceNumber string, airWaybill string) ([]OrderHistory, error)
	}