Save migrations file on db (#215)

* Revert "Migration sql changes (#199)"

This reverts commit 12c834469c.

* Save migrate file on db

* Add message on migration error in lamassu-update

migrations/025-create_trades.js

@@ -2,8 +2,8 @@ var db = require('./db')
 
 exports.up = function (next) {
   var sql = [
-    db.defineEnum('trade_type', "'buy', 'sell'"),
-    `create table if not exists trades (
+    "create type trade_type as enum ('buy', 'sell')",
+    `create table trades (
       id serial PRIMARY KEY,
       type trade_type not null,
       crypto_code text not null,