Fixes, updates for CI configuration

Tox was failing to run due to allowlist_externals not including
run_bashate.sh; changed the way it was called to allow it to work.

Also updated hacking to v6, the latest.

Change-Id: Iec5ddadbb5f819dad5fcf1ef8de9a65b037c99a5

Author: jayofdoom

tox.ini

@@ -30,7 +30,7 @@ commands =
 
 [testenv:pep8]
 deps =
-    hacking>=4.1.0,<5.0.0 # Apache-2.0
+    hacking~=6.0.0 # Apache-2.0
     flake8-import-order==0.17.1 # LGPLv3
     bashate>=0.5.1 # Apache-2.0
     pycodestyle>=2.0.0,<3.0.0 # MIT
@@ -40,7 +40,7 @@ commands =
   bash tools/flake8wrap.sh {posargs}
   # Run bashate during pep8 runs to ensure violations are caught by
   # the check and gate queues.
-  {toxinidir}/tools/run_bashate.sh {toxinidir}/devstack
+  bash {toxinidir}/tools/run_bashate.sh {toxinidir}/devstack
   doc8 README.rst CONTRIBUTING.rst doc/source --ignore D001
 
 [testenv:docs]