Fix: Add return type declarations

Author: localheinz

generator/tests/DateTimeImmutableTest.php

@@ -9,7 +9,7 @@
 
 class DateTimeImmutableTest extends TestCase
 {
-    protected function setUp()
+    protected function setUp(): void
     {
         require_once __DIR__ . '/../../lib/Exceptions/SafeExceptionInterface.php';
         require_once __DIR__ . '/../../generated/Exceptions/DatetimeException.php';
@@ -142,7 +142,7 @@ public function testSerialize()
         $this->assertEquals($safeDatetime->getTimestamp(), $newDatetime->getTimestamp());
         $this->assertEquals($safeDatetime->getTimezone(), $newDatetime->getTimezone());
     }
-    
+
     public function testComparaison(): void
     {
         $safeDateTime = new \Safe\DateTimeImmutable();
@@ -165,4 +165,4 @@ public function testEquals(): void
         $this->assertEquals($phpDateTime, $safeDateTime2);
         $this->assertEquals($safeDateTime1, $safeDateTime2);
     }
-}
+}

generator/tests/DateTimeTest.php

@@ -9,7 +9,7 @@
 
 class DateTimeTest extends TestCase
 {
-    protected function setUp()
+    protected function setUp(): void
     {
         require_once __DIR__ . '/../../lib/Exceptions/SafeExceptionInterface.php';
         require_once __DIR__ . '/../../generated/Exceptions/DatetimeException.php';
@@ -51,4 +51,4 @@ public function testModify(): void
         $this->assertInstanceOf(DateTime::class, $datetime);
         $this->assertEquals('7-4-2017', $datetime->format('j-n-Y'));
     }
-}
+}