Updated from global requirements

Change-Id: I958576f5679ed176107d9cb9a4bf0dd1ff00b054
diff --git a/test-requirements.txt b/test-requirements.txt
index f7d63a8..844d32c 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -3,7 +3,7 @@
 # process, which may cause wedges in the gate later.
 hacking<0.13,>=0.12.0 # Apache-2.0
 # needed for doc build
-sphinx!=1.3b1,<1.4,>=1.2.1 # BSD
+sphinx>=1.5.1 # BSD
 oslosphinx>=4.7.0 # Apache-2.0
 reno>=1.8.0 # Apache-2.0
 mock>=2.0 # BSD