feat: rate limiter, users table, validation, servers split up, graceful quit, user functions

projects/greenlight/migrations/000004_create_users_table.down.sql

@@ -0,0 +1,2 @@
+DROP TABLE IF EXISTS users;
+

projects/greenlight/migrations/000004_create_users_table.up.sql

@@ -0,0 +1,10 @@
+CREATE TABLE IF NOT EXISTS users (
+    id bigserial PRIMARY KEY,
+    created_at timestamp(0) with time zone NOT NULL DEFAULT NOW(),
+    name text NOT NULL,
+    email citext UNIQUE NOT NULL,
+    password_hash bytea NOT NULL,
+    activated bool NOT NULL,
+    version integer NOT NULL DEFAULT 1
+);
+