Features/create response

In order for partial response form to work

1. Update rants_controller#show as follows:

```
 def show #get particular rant
    @rant = Rant.find(params[:id])
    @responses = @rant.responses
    @response = @rant.responses.build
  end
```

2. Add the following code to rants/show.html.erb:

```
<div class="response-form">
  <div class="errors"></div>
  <%= render 'responses/form', rant: @rant, response: @response %>
</div>
```