Remove Python 2.6 from setup.cfg
Remove Python 2.6 from setup.cfg

Python 2.6 support is dropped so it should be removed from setup.cfg.

Change-Id: I28b205c8a8027de4168b65f272983b38bb09dd2d

bacaldwell/ironic,pshchelo/ironic,pshchelo/ironic,ramineni/myironic,openstack/ironic,supermari0/ironic,bacaldwell/ironic,ionutbalutoiu/ironic,dims/ironic,rdo-management/ironic,redhat-openstack/ironic,naterh/ironic,rackerlabs/ironic,ionutbalutoiu/ironic,openstack/ironic,dims/ironic,devananda/ironic,hpproliant/ironic,naototty/vagrant-lxc-ironic,NaohiroTamura/ironic,SauloAislan/ironic,Tan0/ironic,naototty/vagrant-lxc-ironic,NaohiroTamura/ironic,SauloAislan/ironic