Update oslo.utils minimal version
Commit Ib301466bb0a1996997c63599918fa96059a927bd added the usage
of oslo_utils md5 api which was added only in release 4.7.0.
Updating the requirements to accomodate this.
In addition, changing the requirements for other dependent libraries
Change-Id: Ia86208975cdc2e4261cb6cb20547d76ddb3ec571
diff --git a/requirements.txt b/requirements.txt
index d84116b..eae5427 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -12,7 +12,7 @@
oslo.log>=3.36.0 # Apache-2.0
stestr>=1.0.0 # Apache-2.0
oslo.serialization!=2.19.1,>=2.18.0 # Apache-2.0
-oslo.utils>=3.33.0 # Apache-2.0
+oslo.utils>=4.7.0 # Apache-2.0
six>=1.10.0 # MIT
fixtures>=3.0.0 # Apache-2.0/BSD
PyYAML>=3.12 # MIT