Refactor sluggable concern spec

spec/models/concerns/sluggable.rb

@@ -3,13 +3,12 @@ require 'spec_helper'
 shared_examples_for 'sluggable' do
 
   describe 'generate_slug' do
-    before do
-      create(described_class.name.parameterize.tr('-', '_').to_sym, name: "Marlo Brañido Carlo")
-    end
+    let(:factory_name) { described_class.name.parameterize('_').to_sym }
+    let(:sluggable) { create(factory_name, name: "Marló Brañido Carlo") }
 
     context "when a new sluggable is created" do
       it "gets a slug string" do
-        expect(described_class.last.slug).to eq("marlo-branido-carlo")
+        expect(sluggable.slug).to eq("marlo-branido-carlo")
       end
     end
   end