Updated from global requirements

Change-Id: Ib75d893519638741c0de70f8955f2d7dfdbd202e
diff --git a/requirements.txt b/requirements.txt
index c0a9254..59d6856 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -13,11 +13,11 @@
 testrepository>=0.0.18
 pyOpenSSL>=0.14
 oslo.concurrency>=2.3.0 # Apache-2.0
-oslo.config>=2.3.0 # Apache-2.0
+oslo.config>=2.6.0 # Apache-2.0
 oslo.i18n>=1.5.0 # Apache-2.0
 oslo.log>=1.8.0 # Apache-2.0
-oslo.serialization>=1.4.0 # Apache-2.0
-oslo.utils>=2.0.0 # Apache-2.0
+oslo.serialization>=1.10.0 # Apache-2.0
+oslo.utils!=2.6.0,>=2.4.0 # Apache-2.0
 six>=1.9.0
 iso8601>=0.1.9
 fixtures>=1.3.1