*** Bug 1578925 has been marked as a duplicate of this bug. ***

This is an issue on the Ansible Tower build side.

Adding info from my debugging and an email here:

rpm versions:

[root@localhost setup]# rpm -qa | grep ansible
ansible-tower-setup-3.1.6-1.el7at.x86_64
ansible-tower-server-3.1.6-1.el7at.x86_64
ansible-2.4.4.0-1.el7ae.noarch

setup.log traceback:

Traceback (most recent call last):
  File "/bin/tower-manage", line 9, in <module>
    load_entry_point('ansible-tower==3.1.6', 'console_scripts', 'tower-manage')()
  File "/lib/python2.7/site-packages/awx/__init__.py", line 105, in manage
  File "/var/lib/awx/venv/tower/lib/python2.7/site-packages/django/core/management/__init__.py", line 354, in execute_from_command_line
    utility.execute()
  File "/var/lib/awx/venv/tower/lib/python2.7/site-packages/django/core/management/__init__.py", line 328, in execute
    django.setup()
  File "/var/lib/awx/venv/tower/lib/python2.7/site-packages/django/__init__.py", line 18, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/var/lib/awx/venv/tower/lib/python2.7/site-packages/django/apps/registry.py", line 85, in populate
    app_config = AppConfig.create(entry)
  File "/var/lib/awx/venv/tower/lib/python2.7/site-packages/django/apps/config.py", line 119, in create
    import_module(entry)
  File "/usr/lib64/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/lib/python2.7/site-packages/awx/sso/__init__.py", line 12, in <module>
AttributeError: 'module' object has no attribute 'initialize'

Update from Tower engineering:
> we have reproduced this by installing the brew build of Tower 3.1.6 on RHEL 7.5, and have confirmed that the problem is related to dm.xmlsec.binding.  If we rebuild this natively on 7.5 then it works - so the problem is either that there's a problem when building on 7.2 and running on 7.5, or that there was some kind of build issue with the brew 3.1.6 RPMs.  Shane is currently working on it.