Deal transformer (#19)

db/migrations/1536615440_create_deal_table.down.sql

@@ -0,0 +1 @@
+DROP TABLE maker.deal;

db/migrations/1536615440_create_deal_table.up.sql

@@ -0,0 +1,8 @@
+CREATE TABLE maker.deal (
+  id            SERIAL PRIMARY KEY,
+  header_id     INTEGER NOT NULL REFERENCES headers (id) ON DELETE CASCADE,
+  bid_id        NUMERIC NOT NULL,
+	tx_idx        INTEGER NOT NUll,
+  raw_log       JSONB,
+  UNIQUE (header_id, tx_idx)
+);