Remove method total_seconds in timeuitls

There is no consumer in downstream and in requirments project
file upper-constraints shows oslo.utils==3.8.0 for Mitaka branch, so
it is safe to remove it now.

Change-Id: I44ae4ce59efbfe2fd060aa0ff0e0698470d5ad36

oslo_utils/tests/test_timeutils.py

@@ -231,11 +231,6 @@ class TimeUtilsTest(test_base.BaseTestCase):
         self.assertAlmostEquals(604859.123456,
                                 timeutils.delta_seconds(before, after))
 
-    def test_total_seconds(self):
-        delta = datetime.timedelta(days=1, hours=2, minutes=3, seconds=4.5)
-        self.assertAlmostEquals(93784.5,
-                                timeutils.total_seconds(delta))
-
     def test_iso8601_from_timestamp(self):
         utcnow = timeutils.utcnow()
         iso = timeutils.isotime(utcnow)

oslo_utils/timeutils.py

@@ -298,24 +298,6 @@ def delta_seconds(before, after):
     return delta.total_seconds()
 
 
-@removals.remove(
-    message="use datetime.timedelta.total_seconds()",
-    version="3.1",
-    removal_version="?",
-    )
-def total_seconds(delta):
-    """Return the total seconds of datetime.timedelta object.
-
-    Compute total seconds of datetime.timedelta, datetime.timedelta
-    doesn't have method total_seconds in Python2.6, calculate it manually.
-    """
-    try:
-        return delta.total_seconds()
-    except AttributeError:
-        return ((delta.days * 24 * 3600) + delta.seconds +
-                float(delta.microseconds) / (10 ** 6))
-
-
 def is_soon(dt, window):
     """Determines if time is going to happen in the next window seconds.