requirements: pin pbr>=0.8.2,<2.0

This patch aims to pin pbr>=0.8.2,<2.0 instead of pbr>=0.8.2,<1.0.
To do that, we also need to update test-requirements.txt to pin hacking
to <0.11 (like in current Global OpenStack requirements).
We also need to ignore some hacking rules.

Some distros ship 1.0.1 so it conflicts with the version in
requirements.

Change-Id: I3620c5fe72e49e226f2f5d1e6c36179eb053f424

requirements.txt

@@ -1,2 +1,2 @@
 six
-pbr>=0.8.2,<1.0
+pbr>=0.8.2,<2.0

test-requirements.txt

@@ -1,6 +1,6 @@
 coverage>=3.6
 discover
-hacking>=0.5.6,<0.8
+hacking>=0.5.6,<0.11
 mock
 unittest2
 python-subunit

tox.ini

@@ -36,6 +36,9 @@ commands = {posargs}
 
 [flake8]
 ; E501 line too long (80 > 79 characters)
-ignore = E501
+; H301 one import per line
+; H405 multi line docstring summary not separated with an empty line
+; H501 Do not use locals() for string formatting
+ignore = E501,H301,H405,H501
 show-source = True
 exclude = .venv,.tox,dist,doc,build,*.egg