fix: iterate through migration dirs

lib/data_migrate/data_schema.rb

@@ -30,10 +30,12 @@ def migrated
 
     def versions
       @versions ||= begin
-        versions = []
-        Dir.foreach(DataMigrate::DataMigrator.full_migrations_path) do |file|
-          match_data = DataMigrate::DataMigrator.match(file)
-          versions << match_data[1].to_i if match_data
+        versions = Set.new
+        DataMigrate::DataMigrator.migrations_paths.each do |path|
+          Dir.foreach(path) do |file|
+            match_data = DataMigrate::DataMigrator.match(file)
+            versions << match_data[1].to_i if match_data
+          end
         end
         versions
       end