Bump hacking in test-requirements

The gate-swiftclient-dsvm-functional job takes updates from
openstack/requirements and tries to run functional tests against them.
However, the global requirements recently added environment markers
(like "futures>=3.0;python_version=='2.7' or python_version=='2.6'")
which require pbr>=1.2. pbr was getting capped at 1.0 by hacking<0.9, so
bump it to get newer pbr.

Change-Id: I10af36602d23db78c2863d84c0012835b310bbdd

test-requirements.txt

@@ -1,4 +1,4 @@
-hacking>=0.8.0,<0.9
+hacking>=0.10.0,<0.11
 
 coverage>=3.6
 discover