[python-muranoclient] required oslo.utils version conflicts with nova requirements

[Alexey Deryugin]

Unable to install devstack with murano due to oslo.utils version confict with nova requirements

python-muranoclient requires:
oslo.utils>=1.4.0,<1.5.0

nova requires:
oslo.utils>=1.6.0

devstack installation process fail with error:

+ /usr/local/bin/nova-manage db sync
Traceback (most recent call last):
  File "/usr/local/bin/nova-manage", line 6, in <module>
    from nova.cmd.manage import main
  File "/opt/stack/nova/nova/cmd/manage.py", line 70, in <module>
    from nova.api.ec2 import ec2utils
  File "/opt/stack/nova/nova/api/ec2/__init__.py", line 36, in <module>
    from nova.api.ec2 import apirequest
  File "/opt/stack/nova/nova/api/ec2/apirequest.py", line 30, in <module>
    from nova.api.ec2 import ec2utils
  File "/opt/stack/nova/nova/api/ec2/ec2utils.py", line 31, in <module>
    from nova.objects import base as obj_base
  File "/opt/stack/nova/nova/objects/base.py", line 27, in <module>
    from oslo_utils import versionutils
ImportError: cannot import name versionutils

Steps to reproduce:

1. Clone latest devstack
2. Clone latest murano
3. Copy murano devstack files
3. Deploy devstack