actix-node-benchmark: create tables

actix-node-bench-db-create.sql

CREATE TABLE worker (
	id SERIAL PRIMARY KEY,
	name varchar(255) NOT NULL,
	email varchar(255) NULL,
	score integer DEFAULT 0
);

CREATE TABLE task (
	id SERIAL PRIMARY KEY,
	summary varchar(255) NOT NULL,
	description text NOT NULL,
	assignee_id integer NULL REFERENCES worker,
	created TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);