Remove test duplication between tempest and ntp NetworksTestDHCPv6

NetworksTestDHCPv6 [1] has better
functionality in tempest than in neutron-tempest-plugin, so with
removing these tests from neutron-tempest-plugin we can get rid
of whole module, reducing the test duplications.

[1]https://github.com/openstack/tempest/blob/cc0e9b18170bc796fd8516e41d2ec09236b168aa/tempest/api/network/test_dhcp_ipv6.py#L31

Change-Id: I080b83965acd69c3d1b4693527c1be0b730e80a6
diff --git a/neutron_tempest_plugin/api/test_dhcp_ipv6.py b/neutron_tempest_plugin/api/test_dhcp_ipv6.py
deleted file mode 100644
index 4f2e576..0000000
--- a/neutron_tempest_plugin/api/test_dhcp_ipv6.py
+++ /dev/null
@@ -1,101 +0,0 @@
-# Copyright 2014 OpenStack Foundation
-# All Rights Reserved.
-#
-#    Licensed under the Apache License, Version 2.0 (the "License"); you may
-#    not use this file except in compliance with the License. You may obtain
-#    a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-#    Unless required by applicable law or agreed to in writing, software
-#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-#    License for the specific language governing permissions and limitations
-#    under the License.
-
-import netaddr
-from neutron_lib import constants
-from tempest.lib import decorators
-from tempest.lib import exceptions as lib_exc
-
-from neutron_tempest_plugin.api import base
-from neutron_tempest_plugin import config
-
-CONF = config.CONF
-
-
-class NetworksTestDHCPv6(base.BaseNetworkTest):
-    _ip_version = 6
-
-    def setUp(self):
-        super(NetworksTestDHCPv6, self).setUp()
-        self.addCleanup(self._clean_network)
-
-    @classmethod
-    def skip_checks(cls):
-        super(NetworksTestDHCPv6, cls).skip_checks()
-        msg = None
-        if not CONF.network_feature_enabled.ipv6:
-            msg = "IPv6 is not enabled"
-        elif not CONF.network_feature_enabled.ipv6_subnet_attributes:
-            msg = "DHCPv6 attributes are not enabled."
-        if msg:
-            raise cls.skipException(msg)
-
-    @classmethod
-    def resource_setup(cls):
-        super(NetworksTestDHCPv6, cls).resource_setup()
-        cls.network = cls.create_network()
-
-    def _remove_from_list_by_index(self, things_list, elem):
-        for index, i in enumerate(things_list):
-            if i['id'] == elem['id']:
-                del things_list[index]
-                return
-
-    def _clean_network(self):
-        body = self.client.list_ports()
-        ports = body['ports']
-        for port in ports:
-            if (port['device_owner'].startswith(
-                    constants.DEVICE_OWNER_ROUTER_INTF) and
-                port['device_id'] in [r['id'] for r in self.routers]):
-                self.client.remove_router_interface_with_port_id(
-                    port['device_id'], port['id']
-                )
-            else:
-                if port['id'] in [p['id'] for p in self.ports]:
-                    self.client.delete_port(port['id'])
-                    self._remove_from_list_by_index(self.ports, port)
-        body = self.client.list_subnets()
-        subnets = body['subnets']
-        for subnet in subnets:
-            if subnet['id'] in [s['id'] for s in self.subnets]:
-                self.client.delete_subnet(subnet['id'])
-                self._remove_from_list_by_index(self.subnets, subnet)
-        body = self.client.list_routers()
-        routers = body['routers']
-        for router in routers:
-            if router['id'] in [r['id'] for r in self.routers]:
-                self.client.delete_router(router['id'])
-                self._remove_from_list_by_index(self.routers, router)
-
-    @decorators.idempotent_id('98244d88-d990-4570-91d4-6b25d70d08af')
-    def test_dhcp_stateful_fixedips_outrange(self):
-        """Test DHCP Stateful fixed IPs out of range
-
-        When port gets IP address from fixed IP range it
-        shall be checked if it's from subnets range.
-        """
-        kwargs = {'ipv6_ra_mode': 'dhcpv6-stateful',
-                  'ipv6_address_mode': 'dhcpv6-stateful'}
-        subnet = self.create_subnet(self.network, **kwargs)
-        ip_range = netaddr.IPRange(subnet["allocation_pools"][0]["start"],
-                                   subnet["allocation_pools"][0]["end"])
-        for i in range(1, 3):
-            ip = netaddr.IPAddress(ip_range.last + i).format()
-            self.assertRaises(lib_exc.BadRequest,
-                              self.create_port,
-                              self.network,
-                              fixed_ips=[{'subnet_id': subnet['id'],
-                                          'ip_address': ip}])