Order imports in alphabetical order (8/9)

This patch is one in a series to re-enable H306 style check rule
(imports are in alphabetical order).
It touches second half of tests (starting from test_n*).

Implements: blueprint reduce-flake8-ignored-rules (partial)
Change-Id: I5561d90a67eb5dc882200d432fda6b162011ac41
OS::Nova::Server depend on subnets related to nets

Nova supports creating network interfaces by network ID however
if the network and the subnet are part of the same stack as this
server then a race occurs between the creation of the subnet and
the creation of the server. Likewise for delete the subnet cannot
be deleted until all ports are removed from it.

This change adds the same add_dependencies workaround to
OS::Nova::Server that OS::Neutron::Port and OS::Neutron::RouterGateway
have.

The confirmation that this change fixes the race will be confirmed
by tempest test NeutronResourcesTestJSON once
https://review.openstack.org/#/c/82393/ lands.

Change-Id: I626b976446cda709d96823c9de331eafc29d3c68
Closes-Bug: #1243992
Imported Translations from Transifex

Change-Id: I54d40a2c1d46c1f06e48034c52be5107bf80a62a
Don't log exception for None timeout_mins

If a request contains a timeout_mins key but it is None (which is
now the case for all requests sent via python-heatclient), we log
an exception, but really we just want to ignore the value and
continue (as well as other "None" values, ie '0' which was the
previous default for no key)

So split the test for a key and conversion to int, and only log
the exception if there is an error doing the type conversion,
not if we get a value which implies ignoring/doing nothing.

Change-Id: I6b8d1f053b47fd4c22a5df636481a95bd046b1df
Closes-Bug: #1297759
Merge "Imported Translations from Transifex"
Merge "Don't log exception for None timeout_mins"
Merge "OS::Nova::Server depend on subnets related to nets"
Merge "Order imports in alphabetical order (8/9)"