Make milestone's description a required attribute

app/models/budget/investment/milestone.rb

@@ -10,12 +10,14 @@ class Budget
       belongs_to :investment
 
       validates :title, presence: true
+      validates :description, presence: true
       validates :investment, presence: true
       validates :publication_date, presence: true
 
       def self.title_max_length
         80
       end
+
     end
   end
 end

spec/models/budget/investment/milestone_spec.rb

@@ -14,6 +14,11 @@ describe "Budget::Investment::Milestone" do
       expect(milestone).to_not be_valid
     end
 
+    it "Should not be valid without a description" do
+      milestone.description = nil
+      expect(milestone).to_not be_valid
+    end
+
     it "Should not be valid without an investment" do
       milestone.investment_id = nil
       expect(milestone).to_not be_valid