Allow override of os-brick library used by cinder

os-brick code was pulled out of cinder and made into its own library
https://review.openstack.org/#/c/155552/

added to requirements:
https://review.openstack.org/#/c/177372/

Integration tests were added
https://review.openstack.org/#/c/188156/

But they still use the version of os-brick from pip.

This change updates devstack to pull in the changes from
os-brick patch sets instead, when configured to do so.

Needed-by: Id2bc10782847861fe4bb5e9e46245654450e38fd

Change-Id: I5359dd37dfe94bd469d5ca35f9fbaeda61b5fac4
diff --git a/tests/test_libs_from_pypi.sh b/tests/test_libs_from_pypi.sh
index 8210d0a..336a213 100755
--- a/tests/test_libs_from_pypi.sh
+++ b/tests/test_libs_from_pypi.sh
@@ -39,7 +39,7 @@
 ALL_LIBS+=" python-openstackclient oslo.rootwrap oslo.i18n"
 ALL_LIBS+=" python-ceilometerclient oslo.utils python-swiftclient"
 ALL_LIBS+=" python-neutronclient tooz ceilometermiddleware oslo.policy"
-ALL_LIBS+=" debtcollector"
+ALL_LIBS+=" debtcollector os-brick"
 
 # Generate the above list with
 # echo ${!GITREPO[@]}