fix: use go-migrate pkg to init or update db schema

Instead to implement own logic how the database scheme should be updated
or migrated to a newer or older version flucky use now instead the
go-migrate package.

pkg/repository/db/postgres.go

@@ -3,18 +3,24 @@ package db
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
+	"net/url"
 	"time"
 
+	postgresddl "git.cryptic.systems/volker.raschek/flucky/pkg/repository/db/postgres/ddl"
 	"git.cryptic.systems/volker.raschek/flucky/pkg/types"
 	"git.cryptic.systems/volker.raschek/go-logger"
+	"github.com/golang-migrate/migrate/v4"
+	bindata "github.com/golang-migrate/migrate/v4/source/go_bindata"
 )
 
 // Postgres implementation
 type Postgres struct {
-	dbo     *sql.DB
-	flogger logger.Logger
-	queries map[string]string
+	databaseURL *url.URL
+	dbo         *sql.DB
+	flogger     logger.Logger
+	queries     map[string]string
 }
 
 // Close closes the database and prevents new queries from starting. Close then
@@ -420,21 +426,29 @@ func (postgres *Postgres) InsertSensors(ctx context.Context, sensors ...*types.S
 	return tx.Commit()
 }
 
-// Scheme creates all required tables if not exist
-func (postgres *Postgres) Scheme(ctx context.Context) error {
-	for _, query := range []string{
-		postgres.queries["createTableDevices.sql"],
-		postgres.queries["createTableSensors.sql"],
-		postgres.queries["createTableHumidities.sql"],
-		postgres.queries["createTablePressures.sql"],
-		postgres.queries["createTableTemperatures.sql"],
-	} {
-		_, err := postgres.dbo.ExecContext(ctx, query)
-		if err != nil {
-			return err
-		}
+// Migrate creates all required tables if not exist
+func (postgres *Postgres) Migrate(ctx context.Context) error {
+	assetSource := bindata.Resource(postgresddl.AssetNames(), func(query string) ([]byte, error) {
+		return postgresddl.Asset(query)
+	})
+
+	sourceDriver, err := bindata.WithInstance(assetSource)
+	if err != nil {
+		return err
+	}
+
+	m, err := migrate.NewWithSourceInstance("bindata", sourceDriver, postgres.databaseURL.String())
+	if err != nil {
+		return err
+	}
+
+	err = m.Up()
+	switch {
+	case errors.Is(err, migrate.ErrNoChange):
+		return nil
+	default:
+		return err
 	}
-	return nil
 }
 
 // SelectDevice from database