port over lightSync updates from maker repo

db/migrations/1531758090_create_headers_table.up.sql

@@ -2,7 +2,8 @@ CREATE TABLE public.headers (
   id                    SERIAL PRIMARY KEY,
   hash                  VARCHAR(66),
   block_number          BIGINT,
-  raw                   bytea,
+  raw                   JSONB,
+  block_timestamp       NUMERIC,
   eth_node_id           INTEGER,
   eth_node_fingerprint  VARCHAR(128),
   CONSTRAINT eth_nodes_fk FOREIGN KEY (eth_node_id)

db/migrations/1532468317_create_checked_headers_table.down.sql

@@ -0,0 +1 @@
+DROP TABLE public.checked_headers;

db/migrations/1532468317_create_checked_headers_table.up.sql

@@ -0,0 +1,5 @@
+CREATE TABLE public.checked_headers (
+  id                  SERIAL PRIMARY KEY,
+  header_id           INTEGER UNIQUE NOT NULL REFERENCES headers (id) ON DELETE CASCADE,
+  price_feeds_checked BOOLEAN NOT NULL DEFAULT FALSE
+);