def add
usage = 'heroku ssl:add <pem> <key>'
raise CommandFailed, "Missing pem file. Usage:\n#{usage}" unless pem_file = args.shift
raise CommandFailed, "Missing key file. Usage:\n#{usage}" unless key_file = args.shift
raise CommandFailed, "Could not find pem in #{pem_file}" unless File.exists?(pem_file)
raise CommandFailed, "Could not find key in #{key_file}" unless File.exists?(key_file)
pem = File.read(pem_file)
key = File.read(key_file)
info = heroku.add_ssl(app, pem, key)
display "Added certificate to #{info['domain']}, expiring in #{info['expires_at']}"
end