Pin back os-ken to 2.10.0

os-ken 2.11.0 broke neutron CI, until
we have a fix reverting os-ken to working
version.
Also excluded broken releases in global-requirements.

Related-Bug: #2088285
Change-Id: I3f8d20614e1477676b56b6b1631f72d66a99f486

global-requirements.txt

@@ -353,7 +353,7 @@ os-apply-config  # Apache-2.0
 os-brick!=2.8.0  # Apache-2.0
 os-client-config  # Apache-2.0
 os-collect-config  # Apache-2.0
-os-ken  # Apache-2.0
+os-ken!=2.11.0,!=2.11.1  # Apache-2.0
 os-refresh-config  # Apache-2.0
 os-resource-classes  # Apache-2.0
 os-service-types  # Apache-2.0

upper-constraints.txt

@@ -291,7 +291,7 @@ django-pyscss===2.0.3
 uritemplate===4.1.1
 docutils===0.21.2
 threadpoolctl===3.5.0
-os-ken===2.11.1
+os-ken===2.10.0
 ujson===5.10.0
 selenium===3.141.0
 mistral-lib===3.0.0