Switch to hacking 2.x

This bumps the version of flake8 and pycodestyle to something much
newer, which resolves a long-standing warning about nested sets and
allows us to use new fangled features like f-strings if we so choose.

Change-Id: I0bb9077f1cea2243b7945e87cfa140f9cf89d558
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>

test-requirements.txt

@@ -2,14 +2,13 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-hacking>=1.1.0,<1.2.0 # Apache-2.0
+hacking>=2.0<3.0
 coverage!=4.4,>=4.0 # Apache-2.0
 ddt>=1.0.1 # MIT
 fixtures>=3.0.0 # Apache-2.0/BSD
 mock>=3.0.0 # BSD
 psycopg2>=2.7 # LGPL/ZPL
 PyMySQL>=0.7.6 # MIT License
-pycodestyle>=2.0.0 # MIT License
 python-barbicanclient>=4.5.2 # Apache-2.0
 python-ironicclient!=2.7.1,>=2.7.0 # Apache-2.0
 requests-mock>=1.2.0 # Apache-2.0