support db migrations

assets/db/migrations/0001_init.up.sql

@@ -0,0 +1,13 @@
+CREATE TABLE IF NOT EXISTS public.stats (
+  device_id TEXT NOT NULL,
+  inc_traffic INT NOT NULL DEFAULT 0,
+  out_traffic INT NOT NULL DEFAULT 0,
+  inc_rps INT NOT NULL DEFAULT 0,
+  read_rps INT NOT NULL DEFAULT 0,
+  write_rps INT NOT NULL DEFAULT 0,
+  updated_at TIMESTAMP WITHOUT TIME ZONE DEFAULT NOW()
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS
+  stats_by_device_id_idx ON public.stats(device_id);
+