31-admin-student-list-page

##Admin student list page
* New Controller: `admin/students`
* Only action (for now): `index`
* Create template (of course): `views/admin/students/index.html.slim`
* Display a `<table>` where there is a `<tr>` per student
* The table can display the following fields: id, name, email, phone, created_at
* Controllers Tests