Move jwt keys to database

Moved code for it to one place
Updated to chi v5

backend/embed/migrations/sqlite/20201013035318_initial_schema.sql

@@ -1,5 +1,15 @@
 -- migrate:up
 
+CREATE TABLE IF NOT EXISTS `keys`
+(
+	id INTEGER PRIMARY KEY AUTOINCREMENT,
+	created_at INTEGER NOT NULL DEFAULT 0,
+	updated_at INTEGER NOT NULL DEFAULT 0,
+	is_deleted INTEGER NOT NULL DEFAULT 0,
+	public_key TEXT NOT NULL,
+	private_key TEXT NOT NULL
+);
+
 CREATE TABLE IF NOT EXISTS `user`
 (
 	id INTEGER PRIMARY KEY AUTOINCREMENT,