Change the wording if we update the order

src/order/PurchaseOrder.js

@@ -118,7 +118,9 @@ class PurchaseOrder extends React.Component {
         {formEntries}
         <Form.Group as={Row}>
           <Col className="text-right">
-            <Button type="submit">Realizar pedido</Button>
+            <Button type="submit">
+              {this.props.purchase ? "Actualizar" : "Realizar"} pedido
+            </Button>
           </Col>
           <Col>
             <h3>Total: {printMoney(this.state.total)}€</h3>