set activerecord whitelist_attributes to true

spec/models/key_spec.rb

@@ -6,6 +6,11 @@ describe Key do
     it { should belong_to(:project) }
   end
 
+  describe "Mass assignment" do
+    it { should_not allow_mass_assignment_of(:project_id) }
+    it { should_not allow_mass_assignment_of(:user_id) }
+  end
+
   describe "Validation" do
     it { should validate_presence_of(:title) }
     it { should validate_presence_of(:key) }