exclude config/ from rubocop styling, more style fixes

.rubocop.yml

@@ -128,3 +128,4 @@ AllCops:
     - 'db/schema.rb'
     - 'vendor/bundle/**/*'
     - 'bundle/**/*'
+    - 'config/**/*'

app/controllers/admin/registration_periods_controller.rb

@@ -36,7 +36,7 @@ module Admin
         redirect_to admin_conference_registration_period_path(@conference.short_title),
                     notice: 'Registration Period successfully updated.'
       else
-        flash[:alert] = "A error prohibited the Registration Period from being saved: " \
+        flash[:alert] = 'A error prohibited the Registration Period from being saved: ' \
         "#{@registration_period.errors.full_messages.join('. ')}."
         render :edit
       end

spec/controllers/admin/registration_periods_controller_spec.rb

@@ -162,4 +162,3 @@ describe Admin::RegistrationPeriodsController do
 
   end
 end
-

spec/features/registration_periods_spec.rb

@@ -17,7 +17,7 @@ feature RegistrationPeriod do
 
       click_button 'Save Registration Period'
       expect(flash).
-          to eq("A error prohibited the Registration Period from being saved: " \
+          to eq('A error prohibited the Registration Period from being saved: ' \
           "Start date can't be blank. End date can't be blank.")
 
       page.

spec/views/conference/show.html.haml_spec.rb

@@ -1,7 +1,7 @@
 require 'spec_helper'
 describe 'conference/show.html.haml' do
   before(:each) do
-    allow(view).to receive(:date_string).and_return("January 17 - 21 2014")
+    allow(view).to receive(:date_string).and_return('January 17 - 21 2014')
     @conference = create(:conference,
                          sponsor_email: 'example@example.com')