Fix schema

postgres/schema/0002_budgets.sql

@@ -0,0 +1,10 @@
+-- +goose Up
+CREATE TABLE budgets (
+    id uuid DEFAULT uuid_generate_v4() PRIMARY KEY,
+    name text NOT NULL,
+    last_modification timestamp with time zone,
+    income_category_id uuid NOT NULL REFERENCES categories (id) DEFERRABLE
+);
+
+-- +goose Down
+DROP TABLE budgets;