Enable RSpec/HookArgument cop and fix issues

To be consistent about before/after arguments, as `:each` or `:example`
 are same and default scopes, best not to send an argument in those
 scenarios.

Read about cop at http://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/HookArgument

spec/controllers/comments_controller_spec.rb

@@ -3,7 +3,7 @@ require 'rails_helper'
 describe CommentsController do
 
   describe 'POST create' do
-    before(:each) do
+    before do
       @process = create(:legislation_process, debate_start_date: Date.current - 3.days, debate_end_date: Date.current + 2.days)
       @question = create(:legislation_question, process: @process, title: "Question 1")
       @user = create(:user, :level_two)