9f60f0f26d
Ansible Galaxy content importer is using format strings [1] which
are supported since Python 3.6. Our Zuul CI job for OpenStack Queens
uses Ubuntu 16.04 LTS (Xenial Xerus) as its base image which has
Python 3.5 only.
Ref.:
[1] b7140d6b3b/galaxy_importer/main.py (L117)
Change-Id: I5d3b2f71937a0e4ab9a8d49df10744f7d95a7de2