Add python 2.6 deprecation comments
Add python 2.6 deprecation comments

Since there are many lines of python 2.6 deprecation, add a comment at
the end so that it further jobs can be added below the list and it's
clear that they are not part of the 2.6 deprecation.

Add comment for python26-jobs about the deprecation.

Change-Id: I02007ba9eee8f6458446b9fb292647804a6c7543

open-switch/infra_project-config,anbangr/osci-project-config,coolsvap/project-config,noorul/os-project-config,noorul/os-project-config,citrix-openstack/project-config,Tesora/tesora-project-config,openstack-infra/project-config,dongwenjuan/project-config,coolsvap/project-config,dongwenjuan/project-config,Tesora/tesora-project-config,open-switch/infra_project-config,citrix-openstack/project-config,anbangr/osci-project-config,openstack-infra/project-config