Add oslo.utils requirement

With the release of oslo.utils, keystoneclient can make use of it
rather than using the functions in oslo-utils.

Change-Id: I1b5392f10f8b67c9c3ac3bc3d2dd06ea08417aa6

requirements.txt

@@ -4,6 +4,7 @@ iso8601>=0.1.9
 lxml>=2.3
 netaddr>=0.7.6
 oslo.config>=1.4.0.0a3
+oslo.utils>=0.1.1
 pbr>=0.6,!=0.7,<1.0
 PrettyTable>=0.7,<0.8
 requests>=1.1