New converters for #180 (Budget)

app/Repositories/Budget/BudgetRepository.php

@@ -74,6 +74,23 @@ class BudgetRepository extends ComponentRepository implements BudgetRepositoryIn
         return true;
     }
 
+    /**
+     * Find a budget.
+     *
+     * @param int $budgetId
+     *
+     * @return Budget
+     */
+    public function find(int $budgetId): Budget
+    {
+        $budget = $this->user->budgets()->find($budgetId);
+        if (is_null($budget)) {
+            $budget = new Budget;
+        }
+
+        return $budget;
+    }
+
     /**
      * @param Budget $budget
      *

app/Repositories/Budget/BudgetRepositoryInterface.php

@@ -17,7 +17,6 @@ use Illuminate\Support\Collection;
 interface BudgetRepositoryInterface
 {
 
-
     /**
      *
      * Same as ::spentInPeriod but corrects journals for a set of accounts
@@ -43,6 +42,15 @@ interface BudgetRepositoryInterface
      */
     public function destroy(Budget $budget);
 
+    /**
+     * Find a budget.
+     *
+     * @param int $budgetId
+     *
+     * @return Budget
+     */
+    public function find(int $budgetId): Budget;
+
     /**
      * @param Budget $budget
      *