Update requirements from OS Global Requirements.

Update requirements.txt and test-requirements.txt from Global Requirements
defined into openstack/requirements project (stable/liberty).

Change-Id: I6c2669cbbf1d7acf72381522dc17a72835dca669
Closes-Bug: #1520149

requirements.txt

@@ -3,8 +3,8 @@
 # process, which may cause wedges in the gate later.
 
 argparse
-pbr>=0.6,!=0.7,<1.0
 Babel>=1.3
-oslo.i18n
-python-keystoneclient>=0.11.1
-six>=1.7.0
+oslo.i18n>=1.5.0    # Apache-2.0
+pbr>=1.6
+python-keystoneclient>=1.6.0,!=1.8.0
+six>=1.9.0

test-requirements.txt

@@ -2,20 +2,18 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-hacking<0.11,>=0.10.0
-
 coverage>=3.6
 discover
+hacking<0.11,>=0.10
+httpretty>=0.8.4,<0.8.7
+mock>=1.2
+oslosphinx>=2.5.0 # Apache-2.0
+oslotest>=1.10.0  # Apache-2.0
 python-subunit>=0.0.18
 sphinx>=1.1.2,!=1.2.0,!=1.3b1,<1.3
-oslosphinx>=2.2.0  # Apache-2.0
-oslotest>=1.2.0  # Apache-2.0
 testrepository>=0.0.18
 testscenarios>=0.4
-testtools>=0.9.36,!=1.2.0
-mock>=1.0,<1.1
-# httpretty>=0.8.4,!=0.8.7
-httpretty>=0.8.8
+testtools>=1.4.0
 
 # Needed for pypi packaging
 wheel