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/018-alter_devices.js

@@ -4,7 +4,7 @@ exports.up = function (next) {
   var sql = [
     'drop table if exists devices',
     'drop table if exists paired_devices',
-    `create table if not exists devices (
+    `create table devices (
       device_id text PRIMARY KEY,
       name text NOT NULL,
       cashbox integer NOT NULL default 0,
@@ -14,7 +14,7 @@ exports.up = function (next) {
       display boolean NOT NULL default TRUE,
       created timestamptz NOT NULL default now()
     )`,
-    db.addColumn('pairing_tokens', 'name', 'text NOT NULL')
+    'alter table pairing_tokens add column name text NOT NULL'
   ]
   db.multi(sql, next)
 }