[refactor]Move constants to configuration file

app/controllers/conferences_controller.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-EVENTS_PER_PAGE = 3
+EVENTS_PER_PAGE = Rails.configuration.conference[:events_per_page]
 
 class ConferencesController < ApplicationController
   include ConferenceHelper

app/helpers/conference_helper.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-DEFAULT_LOGO = 'snapcon_logo.png'
-DEFAULT_COLOR = '#0B3559'
+DEFAULT_LOGO = Rails.configuration.conference[:default_logo]
+DEFAULT_COLOR = Rails.configuration.conference[:default_color]
 
 module ConferenceHelper
   # Return true if only call_for_papers or call_for_tracks or call_for_booths is open

app/mailers/mailbot.rb

@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-SNAPCON_BCC_ADDRESS = 'messages@snap.berkeley.edu'
-EMAIL_TEMPLATE = 'email_template'
-YTLF_TICKET_ID = 50
+SNAPCON_BCC_ADDRESS = Rails.configuration.mailbot[:bcc_address]
+EMAIL_TEMPLATE = Rails.configuration.mailbot[:email_template]
+YTLF_TICKET_ID = Rails.configuration.mailbot[:ytlf_ticket_id]
 
 class Mailbot < ActionMailer::Base
   helper ConferenceHelper

config/application.rb

@@ -66,6 +66,18 @@ module Osem
 
     config.active_job.queue_adapter = :delayed_job
 
+    config.conference = {
+      events_per_page: 3,
+      default_logo:    'snapcon_logo.png',
+      default_color:   '#0B3559'
+    }
+
+    config.mailbot = {
+      bcc_address:    'messages@snap.berkeley.edu',
+      email_template: 'email_template',
+      ytlf_ticket_id: 50
+    }
+
     config.before_configuration do
       env_file = File.join(Rails.root, 'config', 'local_env.yml')
       if File.exist?(env_file)