[Fix gate] Update pbr requirement

Explicit version dependency of pbr is added in requirements.txt.
Also, since pbr already landed and the old version of hacking
seems not work very well with pbr>=2, we should update it to
match global requirement. Minor flake8 issue resolved in
``proliantutils/hpssa/objects.py``.

Change-Id: I5c019ce41606b73fe12d56b871f76ef17224d4fc
Partial-Bug: #1668848

proliantutils/hpssa/objects.py

@@ -568,7 +568,7 @@ class LogicalDrive(object):
                 'volume_name': self.volume_name}
 
 
-class PhysicalDrive:
+class PhysicalDrive(object):
     """Class for PhysicalDrive object."""
 
     def __init__(self, id, properties, parent):

requirements.txt

@@ -1,3 +1,4 @@
+pbr>=2.0.0 # Apache-2.0
 six>=1.9.0
 oslo.concurrency>=1.8.0
 oslo.utils>=1.4.0

setup.py

@@ -3,5 +3,5 @@
 import setuptools
 
 setuptools.setup(
-    setup_requires=['pbr'],
+    setup_requires=['pbr>=2.0.0'],
     pbr=True)

test-requirements.txt

@@ -1,5 +1,5 @@
 mock
-hacking>=0.9.2,<0.10
+hacking!=0.13.0,<0.14,>=0.12.0 # Apache-2.0
 coverage>=3.6 # Apache-2.0
 testrepository>=0.0.18
 testtools>=1.4.0 # MIT