Add *.swo/swp to .gitignore
Add *.swo/swp to .gitignore

I noticed these files weren't being ignored when I accidentally uploaded
one here: https://review.openstack.org/#/c/30648/3

Fixes bug: 1187600

Change-Id: I8570f797e2cc7420dc8a578a9cf68741631cd9f6

openstack/networking-odl,CiscoSystems/networking-odl,citrix-openstack-build/neutron-vpnaas,openstack/neutron-fwaas,openstack/neutron-vpnaas,dougwig/x-neutron-vpnaas,flavio-fernandes/networking-odl,FedericoRessi/networking-odl,openstack/neutron-fwaas,openstack/networking-odl,CiscoSystems/networking-odl,openstack/networking-odl,flavio-fernandes/networking-odl,citrix-openstack-build/neutron-fwaas,mestery/x-stackforge-odl,schoksey/networking-odl,dougwig/x-neutron-fwaas,FedericoRessi/networking-odl,openstack/neutron-vpnaas,schoksey/networking-odl,gaolichuang/neutron-fwaas,gaolichuang/neutron-fwaas