Upgrade rspec-rails to 3.5.2
Upgrade rspec-rails to 3.5.2

This removes the following deprecation:

```
[DEPRECATION] `last_comment` is deprecated.  Please use `last_description`
instead.
```

alphagov/business-support-finder,alphagov/business-support-finder,alphagov/business-support-finder,alphagov/business-support-finder