Adds middleware plugins to Farscape


Adds middleware plugins to farscape so other gems can add crazy middleware to the requests
when you create a class like this it is not destroyed at the end of a test and can cause problems in the future. Better pattern:

```ruby
let(:test_middleware) { Class.new(AvailableMiddleware) }
```
If you need to do more in the class, you can  use a do ..end block on Class.new. This gets torn down then every spec. Will save your bacon over time to use this pattern.