Add evolutions file

```
$ vim conf/evolutions/default/10.sql
$ vim conf/evolutions/default/9.sql
```
Add models

```
$ vim app/models/Begin.scala
$ vim app/models/Tweet.scala
$ vim app/models/User.scala
```
Change controllers

```
$ vim app/controllers/Application.scala
$ vim app/controllers/Users.scala
```
Add evolutions file