Fix Organizer#with spec

Fixes #3
Copying from that issue...

===

```ruby
      def with(data = {})
        @context = data.kind_of?(::LightService::Context) ?
                     data :
                     LightService::Context.make(data)
        self
      end
```

All specs still pass even when it's changed to this:

```ruby
      def with(data = {})
        @context = LightService::Context.make(data)
        self
      end
```

a quick check on spec/organizer_spec.rb says #with should not create a context given that the parameters is a context.