Update glance_store requirement to 0.7.1
Update glance_store requirement to 0.7.1

This release has support for py34, so we can stop using glance_store
directly from git.

Change-Id: I60777b464da28fae4b27bb3d575a07091cea6b45
Depends-On: I4b3fe87fa11465d784f1158142c52e4f09001d27

takeshineshiro/glance,openstack/glance,stevelle/glance,akash1808/glance,takeshineshiro/glance,scripnichenko/glance,stevelle/glance,rajalokan/glance,saeki-masaki/glance,paramite/glance,klmitch/glance,rajalokan/glance,vuntz/glance,vuntz/glance,openstack/glance,paramite/glance,scripnichenko/glance,openstack/glance,ozamiatin/glance,klmitch/glance,akash1808/glance,dims/glance,ozamiatin/glance,saeki-masaki/glance,dims/glance