FactoryGirl.define do
  factory :global_zone, :class => Spree::Zone do
    name 'GlobalZone'
    description { Faker::Lorem.sentence }
    zone_members do |proxy|
      zone = proxy.instance_eval { @instance }
      Spree::Country.all.map do |c|
        zone_member = Spree::ZoneMember.create(:zoneable => c, :zone => zone)
      end
    end
  end

  factory :zone, :class => Spree::Zone do
    name { Faker::Lorem.words }
    description { Faker::Lorem.sentence }
  end
end

FactoryGirl.define do
  factory :global_zone, :class => Spree::Zone do
    name 'GlobalZone'
    description { Faker::Lorem.sentence }
    zone_members do |proxy|
      zone = proxy.instance_eval { @instance }
      Spree::Country.all.map do |c|
        zone_member = Spree::ZoneMember.create(:zoneable => c, :zone => zone)
      end
    end
  end

  factory :zone, :class => Spree::Zone do
    name { Faker::Lorem.sentence }
    description { Faker::Lorem.sentence }
  end
end

Use sentence for zone factory's name
Use sentence for zone factory's name

words returned an array
