replaces uniq with distinct

Uniq is deprecated

app/models/budget/ballot.rb

@@ -6,8 +6,8 @@ class Budget
 
     has_many :lines, dependent: :destroy
     has_many :investments, through: :lines
-    has_many :groups, -> { uniq }, through: :lines
-    has_many :headings, -> { uniq }, through: :groups
+    has_many :groups, -> { distinct }, through: :lines
+    has_many :headings, -> { distinct }, through: :groups
 
     def add_investment(investment)
       lines.create(investment: investment).persisted?