ignore .idea folder in neutron

[ling-yun]

If we use JetBrains PyCharm as python develop tool, JetBrains PyCharm would automatically generate its config folder name .idea in the root dir of your python code. Many Code projects, such as nova and cinder, have ignore .idea folder. Project neutron should also ignore .idea folder.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/117448

[OpenStack Infra (hudson-openstack)]

Change abandoned by mark mcclain (<email address hidden>) on branch: master
Review: https://review.openstack.org/117448
Reason: This is no longer needed to due to other changes that have merged. Please see the comments.

[Armando Migliaccio (armando-migliaccio)]

This bug is > 172 days without activity. We are unsetting assignee and milestone and setting status to Incomplete in order to allow its expiry in 60 days.

If the bug is still valid, then update the bug status.

[Launchpad Janitor (janitor)]

[Expired for neutron because there has been no activity for 60 days.]