Add DailyBalance type.

src/operations/dailyBalance.ts

@@ -0,0 +1,9 @@
+// vim: set tw=80 ts=2 sw=2 sts=2 :
+
+export class DailyBalance {
+    public operation_date: string;
+    public expenses: number;
+    public revenues: number;
+    public income: number;
+    public balance: number;
+}