Bump hacking min version to 3.0.1

hacking 3.0.1 fix the pinning of flake8 to avoid bringing in a new
version with new checks.

bumping the min version for hacking so that any older hacking versions
which auto adopt the new checks are not used.

Depends-On: https://review.opendev.org/#/c/728335/

Change-Id: Ie00c10332bd7110169dbb150d601c157b6694d05

test-requirements.txt

@@ -2,7 +2,7 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-hacking>=2.0<2.1
+hacking>=3.0.1,<3.1.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
 ddt>=1.0.1 # MIT
 fixtures>=3.0.0 # Apache-2.0/BSD