users#index, users#show

### Get user list
`GET http://localhost:3000/api/users.json`
```json
{
    "users": [
        {
            "id": 1,
            "email": "admin@ec.hokudai.ac.jp",
            "full_name": "admin admin",
            "handle_name": "admin",
            "birthday": "1990-01-01",
            "email_mobile": "admin@example.com",
            "admin": true,
            "graduation_year_id": 1,
            "errors": {}
        },
        {
            "id": 2,
            ...
        }
    ]
}
```

### Get single user
`GET http://localhost:3000/api/users/1.json`
```json
{
    "user": {
        "id": 1,
        "email": "admin@ec.hokudai.ac.jp",
        "full_name": "admin admin",
        "handle_name": "admin",
        "birthday": "1990-01-01",
        "email_mobile": "admin@example.com",
        "admin": true,
        "graduation_year_id": 1,
        "errors": {}
    }
}
```