add migrations

migrations/000_migrations_init.py

@@ -0,0 +1,27 @@
+import os
+from db import BotDB
+
+
+BotDB = BotDB()
+
+
+def get_filename():
+    """Возвращает имя файла без расширения."""
+    filename = os.path.basename(__file__)
+    filename = os.path.splitext(filename)[0]
+    return filename
+
+
+def main():
+    migrations_init = """
+        CREATE TABLE IF NOT EXISTS migrations (
+            version INTEGER PRIMARY KEY NOT NULL,
+            script_name TEXT NOT NULL,
+            created_at TEXT
+        );
+    """
+    BotDB.create_table(migrations_init)
+    BotDB.update_version(0, get_filename())
+
+if __name__ == "__main__":
+    main()