Deprecate is_bsd and remove its use in test suite

We do not support running neutron on bsd (e.g. macos) systems, so the
function has no reason to exist. The only user is neutron test suite and
it's proposed to remove its usage there too:

If5e06dcf3a323692137d2c7cbb8ca725d9d7d821

Note: This patch reintroduces debtcollector dependency to handle the
deprecation process.

Change-Id: I7db4698a247df18cf5fa1ce7f8ede5c5f27ecfa0

neutron_lib/tests/tools.py

@@ -18,6 +18,7 @@ import platform
 import random
 import time
 
+from debtcollector import removals
 import netaddr
 
 from neutron_lib.utils import helpers
@@ -37,6 +38,7 @@ class UnorderedList(list):
         return not self == other
 
 
+@removals.remove
 def is_bsd():
     """Return True on BSD-based systems."""
 

neutron_lib/tests/unit/api/test_converters.py

@@ -180,8 +180,7 @@ class TestConvertIPv6AddrCanonicalFormat(base.BaseTestCase):
             '2001:0db8:0:0:0:0:0:0001')
         self.assertEqual('2001:db8::1', result)
 
-    @testtools.skipIf(tools.is_bsd(), 'bug/1484837')
-    def test_convert_ipv6_compressed_address_OSX_skip(self):
+    def test_convert_ipv6_compressed_address(self):
         result = converters.convert_ip_to_canonical_format(
             '2001:db8:0:1:1:1:1:1')
         self.assertEqual('2001:db8:0:1:1:1:1:1', result)

requirements.txt

@@ -26,4 +26,4 @@ osprofiler>=1.4.0 # Apache-2.0
 setproctitle>=1.1.10 # BSD
 WebOb>=1.7.1 # MIT
 os-traits>=0.9.0 # Apache-2.0
-
+debtcollector>=3.0.0  # Apache-2.0