`rails generate model mailer name:string enabled:boolean sent_date:datetime tier1_floor:integer tier1_ceiling:integer 'tier1_price:decimal{5,2}' tier2_floor:integer tier2_ceiling:integer 'tier2_price:decimal{5,2}' tier3_floor:integer tier3_ceiling:integer 'tier3_price:decimal{5,2}' tier4_floor:integer tier4_ceiling:integer 'tier4_price:decimal{5,2}'`
Add ApplicationController#authenticate_admin! method