add: schema migration scripts

sql/migration_0.sql

@@ -0,0 +1,38 @@
+create table meta
+(
+    version_num int not null
+);
+
+create table controllers
+(
+    id          VARCHAR(33) not null
+        primary key
+        unique,
+    name        VARCHAR(128),
+    ip          VARCHAR(16),
+    port        INTEGER,
+    relay_count INTEGER,
+    active      BOOLEAN     not null
+);
+
+create table relays
+(
+    id                 INTEGER     not null
+        primary key
+        unique,
+    name               VARCHAR(128),
+    number             INTEGER     not null,
+    controller_id      VARCHAR(33) not null
+        references controllers (id),
+    active_schedule_id VARCHAR(33)
+        references schedules
+);
+
+create table schedules
+(
+    id      VARCHAR(33) not null
+        primary key
+        unique,
+    name    VARCHAR(128),
+    periods BLOB
+);