Added unit tests for CORS middleware
Added unit tests for CORS middleware

A simple set of sanity tests that assert that the CORS middleware
is correctly triggered.

Change-Id: I4c40d748caf404a152bcd2b60a6b9a4dbe2cff9b

devananda/ironic,dims/ironic,NaohiroTamura/ironic,bacaldwell/ironic,bacaldwell/ironic,dims/ironic,openstack/ironic,pshchelo/ironic,ionutbalutoiu/ironic,NaohiroTamura/ironic,SauloAislan/ironic,ionutbalutoiu/ironic,pshchelo/ironic,openstack/ironic,SauloAislan/ironic,hpproliant/ironic