Separate tmp migrations dir from home in join

- enable separator between home and migrations dir

pkg/plugin/manager/manager.go

@@ -73,7 +73,7 @@ func (m *manager) RunMigrations() error {
 // Setup a temporary directory to hold transformer db migrations
 func (m *manager) setupMigrationEnv() error {
 	var err error
-	m.tmpMigDir, err = helpers.CleanPath(filepath.Join("$GOPATH/src", m.GenConfig.Home+".plugin_migrations"))
+	m.tmpMigDir, err = helpers.CleanPath(filepath.Join("$GOPATH/src", m.GenConfig.Home, ".plugin_migrations"))
 	if err != nil {
 		return err
 	}