Update Sphinx version

The api-ref document needs a newer sphinx version, allow a 1.2 Sphinx
version to be used - like it's used in global-requirements.txt.

Change-Id: I9183cc56753fbe7e41206c6a9081899df5c3919a
Needed-By: Ifebc65b188c4f2ba35b61c0deae5ec24401df7f9

Author: ajaeger

test-requirements.txt

@@ -9,7 +9,7 @@ nose
 nosexcover
 nosehtmloutput
 oslosphinx
-sphinx>=1.1.2,<1.2
+sphinx>=1.1.2,!=1.2.0,!=1.3b1,<1.3  # BSD
 os-testr>=0.4.1
 mock>=1.0
 python-swiftclient