Fix isinstance assertions

self.assertIsInstance is preferred over assert(isinstance(..)). See feedback in:
https://review.openstack.org/#/c/102754/1/neutron/tests/unit/test_extension_security_group.py

Change-Id: I9dd6141d8f25961eb42a390b45e6d94d482afc1c
Omit mode keyword when spawning dnsmasq with some ipv6 subnets

Fix UnboundLocalError for certain cases of ipv6 subnets

Closes-Bug: #1335959
Change-Id: I5e4b94d9ba1b13b72e2300b53d5638968e0d3401
Merge "Fix isinstance assertions"
Merge "Omit mode keyword when spawning dnsmasq with some ipv6 subnets"
Implementation of LBaaS Version 2

Added alembic migrations that add new tables for the new object model.
Added new loadbalancingv2 extension.
Added new LoadBalancerPluginv2 class to plugin.py module and unit tests.
Added new loadbalancer_dbv2.py module and unit tests.
Added shim layer to translate new plugin to old style driver and vice versa.

Change-Id: I43270fdf9cd52a57274575ecea502f660ff0d5a9
Co-authored-by: Brandon Logan <brandon.logan@rackspace.com>
Co-authored-by: Vijayendra Bhamidipati <vbhamidipati@paypal.com>
Co-authored-by: Craig Tracey <Craig.Tracey@gmail.com>
Co-authored-by: Phillip Toohill <phillip.toohill@rackspace.com>
Co-authored-by: Dustin Lundquist <dustin@null-ptr.net>
Implements: blueprint lbaas-api-and-objmodel-improvement