added global activities (#259)

tests/Invoice/Calculator/AbstractInvoiceCalculatorTest.php

@@ -72,7 +72,7 @@ abstract class AbstractCalculatorTest extends TestCase
             ->setRate(293.27)
             ->setUser(new User())
             ->setActivity((new Activity())->setName('foo'))
-        ;
+            ->setProject((new Project())->setName('bar'));
 
         $model = new InvoiceModel();
         $model->setCustomer($customer);