init rust db backend

lootalot_db/migrations/2019-06-10-123922_create_items/down.sql

@@ -0,0 +1,2 @@
+DROP TABLE items;
+

lootalot_db/migrations/2019-06-10-123922_create_items/up.sql

@@ -0,0 +1,5 @@
+CREATE TABLE items (
+  id INTEGER PRIMARY KEY,
+  name VARCHAR NOT NULL,
+  base_price INTEGER NOT NULL
+);