[BDD] configure no suites for default profile.

When executing `bin/behat` without specifying a profile, an exception is thrown:

```
  [Behat\Behat\Context\Exception\ContextNotFoundException]
  `FeatureContext` context class not found and can not be used.
```

This explicitly configures behat.yml with no suites for default profile, which results in:

```
$ php bin/behat
No scenarios
No steps
0m0.00s (29.85Mb)
```