[stack@undercloud-0 ~]$ source overcloudrc 
[stack@undercloud-0 ~]$ keystone user-create --name ñew --tenant admin
+----------+----------------------------------+
| Property |              Value               |
+----------+----------------------------------+
|  email   |                                  |
| enabled  |               True               |
|    id    | c6a8d83ee6c24ebebe8839e3504936f2 |
|   name   |               ñew                |
| tenantId | 9659e8dce8234c188dd964d8aa4358ad |
| username |               ñew                |
+----------+----------------------------------+
[stack@undercloud-0 ~]$ keystone user-get ñew
+----------+----------------------------------+
| Property |              Value               |
+----------+----------------------------------+
|  email   |                                  |
| enabled  |               True               |
|    id    | c6a8d83ee6c24ebebe8839e3504936f2 |
|   name   |               ñew                |
| tenantId | 9659e8dce8234c188dd964d8aa4358ad |
| username |               ñew                |
+----------+----------------------------------+
[stack@undercloud-0 ~]$ 
[stack@undercloud-0 ~]$ yum list installed | grep python-keystoneclient
python-keystoneclient.noarch     1:1.7.2-2.el7ost       @rhelosp-8.0-puddle

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2018:0532