Compatibility with RSpec-Rails

I'm adding models to my Stealth implementation and I'd like to use rspec-rails but it doesn't seem to be compatible. The generator won't work and even if I skip the generator and add `rails_helper.rb` myself it won't work.

I get this error
```

Failure/Error: require 'rspec/rails'

NameError:
  uninitialized constant ActionView::Template::Handlers::ERB::ENCODING_FLAG
```

