Unfortunately the latest version of Ansible Tower 3.2.1 is not able to connect to CloudForms due to a bug in the inventory file cloudforms.py
If you need a fix for it until it is fixed downstream in the next tower release you can use mine (not supported of course)
The PR is here:
https://github.com/ansible/ansible/pull/31760
fix is here:
https://github.com/ldomb/ansible/blob/fix-cfme-permission-denied-tower-3.2.1/contrib/inventory/cloudforms.py