Add no_code_generation and stop_on_failure to config

fixes issue #352

This adds the following options to `phpspec.yml'

```yaml
no_code_generation: true
stop_on_failure: true
```
please don't use ``$this->container`` here but the argument. Things were done this way on purpose to allow moving the container building to an extenral class more easily in the future (there was some work started for this but never completed)