Install phpspec

The easiest rational way I know to expose SOLID principles violation is
through demonstrating communication of objects. The most straight
forward way to illustrate actual under-the-hood objects communication is
with any modern mockist framework. But because this project doesn't have
its own test suite, we'll start from installing our framework of choice

- We need PhpSpec to demonstrate mixture of concerns and SRP violation
- We need laravel/framework to fullfil Illuminate\Foundation\Application
  dependency
Describe ValidationCommandBus with examples

The next natural step is to actually describe object of interest
retrospectively. It is a tricky process on its own, but with some
experience and luck, we came up with something like this spec.