add project groups to backend.

migrations/postgres/20210418180353_create_table_project_group.sql

@@ -0,0 +1,16 @@
+-- +goose Up
+-- +goose StatementBegin
+CREATE TABLE project_group (
+   project_group_id CHAR(16) NOT NULL PRIMARY KEY,
+   user_id CHAR(36) NOT NULL,
+   name TEXT NOT NULL,
+   abbreviation TEXT NOT NULL,
+   description TEXT NOT NULL,
+   category_names JSONB NOT NULL
+);
+-- +goose StatementEnd
+
+-- +goose Down
+-- +goose StatementBegin
+DROP TABLE IF EXISTS project_group;
+-- +goose StatementEnd

migrations/postgres/20210717135720_add_project_column_project_group_id.sql

@@ -0,0 +1,11 @@
+-- +goose Up
+-- +goose StatementBegin
+ALTER TABLE project
+    ADD COLUMN project_group_id CHAR(16) DEFAULT NULL;
+-- +goose StatementEnd
+
+-- +goose Down
+-- +goose StatementBegin
+ALTER TABLE project
+    DROP COLUMN IF EXISTS project_group_id;
+-- +goose StatementEnd