Revert "Convert existing migrations from timestamp to versioned"

- This reverts commit 4e2536bf421fd9d2c9067d81f30e0f45c6b94fe7.
- Restore timestamped migrations so goose fix can handle ordering
  dynamically with plugins also supplying timestamp based migrations

db/migrations/20180912015839_create_drip_drip.sql

@@ -0,0 +1,20 @@
+-- +goose Up
+CREATE TABLE maker.drip_drip (
+  id            SERIAL PRIMARY KEY,
+  header_id     INTEGER NOT NULL REFERENCES headers (id) ON DELETE CASCADE,
+  ilk           TEXT,
+  log_idx       INTEGER NOT NUll,
+  tx_idx        INTEGER NOT NUll,
+  raw_log       JSONB,
+  UNIQUE (header_id, tx_idx, log_idx)
+);
+
+ALTER TABLE public.checked_headers
+  ADD COLUMN drip_drip_checked BOOLEAN NOT NULL DEFAULT FALSE;
+
+
+-- +goose Down
+DROP TABLE maker.drip_drip;
+
+ALTER TABLE public.checked_headers
+  DROP COLUMN drip_drip_checked;