Improve unit tests for glance.api.middleware.cache module
Improve unit tests for glance.api.middleware.cache module

Add tests for glance.api.middleware.cache module

Fixes: bug #1152053
Change-Id: I6e99c70b0d8ae20011b4ad9bea76d5e4e1dff921

vuntz/glance,cloudbau/glance,takeshineshiro/glance,stevelle/glance,stevelle/glance,jumpstarter-io/glance,JioCloud/glance,darren-wang/gl,redhat-openstack/glance,wkoathp/glance,takeshineshiro/glance,dims/glance,rickerc/glance_audit,kfwang/Glance-OVA-OVF,saeki-masaki/glance,ozamiatin/glance,darren-wang/gl,scripnichenko/glance,JioCloud/glance,akash1808/glance,openstack/glance,vuntz/glance,ntt-sic/glance,openstack/glance,tanglei528/glance,saeki-masaki/glance,cloudbau/glance,ntt-sic/glance,SUSE-Cloud/glance,scripnichenko/glance,paramite/glance,citrix-openstack-build/glance,kfwang/Glance-OVA-OVF,tanglei528/glance,akash1808/glance,klmitch/glance,dims/glance,citrix-openstack-build/glance,jumpstarter-io/glance,rickerc/glance_audit,klmitch/glance,rajalokan/glance,sigmavirus24/glance,ozamiatin/glance,rajalokan/glance,sigmavirus24/glance,SUSE-Cloud/glance,redhat-openstack/glance,openstack/glance,wkoathp/glance,paramite/glance