Add test cases to cover the behavior described in #14.

Author: nuztalgia

tests/test_time.py

@@ -559,6 +559,9 @@ def test_precisedelta_multiple_units(
             "%.4f",
             "23 hours, 59 minutes and 59.9990 seconds",
         ),
+        (dt.timedelta(days=31), "days", "%d", "1 month"),
+        (dt.timedelta(days=31.01), "days", "%d", "1 month and 1 day"),
+        (dt.timedelta(days=92), "days", "%d", "3 months"),
     ],
 )
 def test_precisedelta_custom_format(