Problems using AWS Dynamic Inventory with STS Profiles

ANSIBLE VERSION
ansible 2.3.0.0
  config file = 
  configured module search path = Default w/o overrides
  python version = 2.7.5 (default, Aug  2 2016, 04:20:16) [GCC 4.8.5 20150623 (Red Hat 4.8.5-4)]