Enables RSpec/ExampleWording and fixes all issues

Both avoiding 'should' and repiting 'it' on the tests description
improves reading them and also makes all descriptions consistent.

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

spec/models/legislation/answer_spec.rb

@@ -3,7 +3,7 @@ require 'rails_helper'
 RSpec.describe Legislation::Answer, type: :model do
   let(:legislation_answer) { build(:legislation_answer) }
 
-  it "should be valid" do
+  it "is valid" do
     expect(legislation_answer).to be_valid
   end