fix issues in sales and purchases module.

server/src/database/migrations/20200719153909_create_bills_payments_table.js

@@ -2,6 +2,8 @@
 exports.up = function(knex) {
   return knex.schema.createTable('bills_payments', table => {
     table.increments();
+    table.integer('vendor_id').unsigned();
+    table.decimal('amount', 13, 3).defaultTo(0);
     table.integer('payment_account_id');
     table.string('payment_number');
     table.date('payment_date');