Add spec for the auditable plugin
user
```ruby
require "rails_helper"

describe "Auditable sequel plugin" do
  let(:model_with_plugin) { create :section_note, content: "first content" }

  describe "Model hooks" do
    it "creates an audit record when updated" do
      expect {
        model_with_plugin.update(content: "test")
      }.to change { Audit.count }.by(1)
    end

    it "the new audit record created keeps the record of the changes" do
      model_with_plugin.update(content: "second content")
      result = JSON.parse(model_with_plugin.audits.last.changes)
      
      expect(result["content"][0]).to eq("first content")
      expect(result["content"][1]).to eq("second content")
    end
  end
end
```
assistant