(fix) !spells and !chants returned null value (#40)

__tests__/functions/Roll.js

@@ -6,3 +6,10 @@ describe('rolling dice', () => {
         expect(roll(200, 6).dice).toContain(value);
     });
 });
+
+describe('rolling dice', () => {
+    const expected = [1, 2, 3, 4, 5, 6];
+    test.each(expected)('contains only numbers from 1 to 6', value => {
+        expect(roll(200, 6, 'test').dice).toContain(value);
+    });
+});