added current sql-schema

sql/schema.sql

@@ -0,0 +1,18 @@
+create table twitch_auth_data
+(
+	id bigint auto_increment
+		primary key,
+	twitch_user_id bigint not null,
+	auth_code char(30) not null,
+	access_token char(30) not null,
+	refresh_token char(50) not null
+);
+
+create table twitch_oauth_states
+(
+	id bigint auto_increment
+		primary key,
+	state char(64) not null,
+	valid_until datetime not null
+);
+