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/1509091634946-support_logs.js

@@ -2,11 +2,11 @@ var db = require('./db')
 
 exports.up = function (next) {
   const sql =
-    [`create table if not exists support_logs (
+    [`create table support_logs (
     id uuid PRIMARY KEY,
     device_id text,
     timestamp timestamptz not null default now() )`,
-    db.addColumn('logs', 'server_timestamp', 'timestamptz not null default now()')
+    'alter table logs add column server_timestamp timestamptz not null default now() '
     ]
 
   db.multi(sql, next)