add not->toBeDivisible() tests

Author: faissaloux

Diff for: tests/toBeDivisibleBy.php

@@ -9,6 +9,14 @@
     'odd' => [6, 3],
 ]);
 
+it('passes not', function (): void {
+    expect(8)->not->toBeDivisibleBy(3);
+});
+
 test('failures', function (): void {
     expect(8)->toBeDivisibleBy(3);
 })->throws(ExpectationFailedException::class);
+
+test('failures not', function (): void {
+    expect(8)->not->toBeDivisibleBy(2);
+})->throws(ExpectationFailedException::class);