Nsot

------------------

* Multiple Python 3 compatibility improvements
* Upgraded dependencies
* cryptography => 2.8
* gevent => 1.4.0
* PyYAML => 5.1
* Bower removed from frontend build process, replace with npm
* Interface.name_slug now updates when Device.hostname does

------------------

* Fix 344: Refresh interface address and network assignments each time a
Network object is saved. This was necessary because, if a network object
is reparented, the interfaces that have IPs assigned from the children of
this network object, do not get updated to reflect the new parent network.
The bug fix in this version ensures that the interfaces will always reflect
the correct parent networks.

------------------

* Allow the ``Interface.speed`` to be null. The existing behavior is preserved
where ``speed`` is set to the configured default value when the field is
omitted on Interface creation. It will only be set to a null value if
``None`` is explicitly passed in, or the default is configured to be
``None``.
* Documentation fixes
* Clarify version release process.
* Update ``Circuit`` docs to reflect changes in how addresses are returned
(PR 335).

------------------

* This version reverts PR 222, which was pushed with release v1.4.2. The revert was prompted by
conflicts that this change caused with a few of Dropbox's internal tools. We plan to address
these conflicts and submit a new release once these issues are resolved.
* Fix 121: Enabled forceful parent delete (and reparent) for Network objects.
+ Addresses scenario where a user accidentally adds a network. Previously, if that network had
any children, deleting the network was impossible due to protections on the network database
field. The server changes in this release allow a newly added pynsot flag ``--force-delete`` to
override the native Django ``PROTECT`` safe guard and forcefully delete the network. The only
scenario where this is still not allowed is if the network in question has no parents and it's
children are leaf nodes. In this case, an error is raised.

------------------

* Fix 222: Enhanced set queries to support filtering by concrete object fields.
+ A side effect of enabling this, attribute names now have a constraint which prohibit them from
being the same as a concrete field on the resource that the attribute is being created on.
* Fix 261: Enabled support to enumerate addresses for all child interfaces. Previously the
``Addresses`` column of pynsot's circuits output only displayed the interfaces directly
associated with the circuit. This feature now appends the addresses for the children of those
addresses.

------------------

* Fix bug in ``NsotSerializer.to_internal_value()`` that tried to modify an
immutable QueryDict.
* Fix Bower registry URL (bower.herokuapp.com is deprecated).
* Upgrade Gunicorn to 19.5.0, fixing CVE-2018-1000164.