Fix E402 (module level import not at top of file) pep8 errors
and no longer ignore new failures.
Trivialfix
Change-Id: If9a202f1f322b5b03966c692e33e94b7c872079b
This patch adds ``net-mtu-writable`` API extension that allows to write
to network ``mtu`` attribute.
The patch also adds support for the extension to ml2, as well as covers
the feature with unit and tempest tests. Agent side implementation of
the feature is moved into a separate patch to ease review.
DocImpact: neutron controller now supports ``net-mtu-writable`` API
extension.
APIImpact: new ``net-mtu-writable`` API extension was added.
Related-Bug: #1671634
Change-Id: Ib232796562edd8fa69ec06b0cc5cb752c1467add
Brian Haley