Add migration file.

backend/moonstream/admin/migrations/1_add_abi_backet_and_s3_path.json

@@ -0,0 +1,24 @@
+{
+  "match": {
+    "type": "subscription"
+  },
+  "description": "Add abi to subscription as flag if subscription has abi of contract. Add bucket and s3_path for get abi from S3.",
+  "upgrade": {
+    "update": {
+      "abi": null,
+      "bucket": null,
+      "s3_path": null,
+      "resources_version": 1
+    },
+    "drop_keys": []
+  },
+  "downgrade": {
+    "update": {},
+    "drop_keys": [
+      "abi",
+      "bucket",
+      "s3_path",
+      "resources_version"
+    ]
+  }
+}