My playbook:
 - name: Provision Stack
   tasks:
     - name: launch ansible cloudformation example
       cloudformation:
         stack_name: "ansible-cloudformation"
         state: "present"
         region: "us-east-1"
         disable_rollback: true
         template: "~/cloudformation-example.json"
         tags:
           Stack: "ansible-cloudformation"
error:
Error: fatal: FAILED! => {"changed": false, "failed": true, "msg": "Traceback (most recent call last):\r\n File \"/home/ec2-user/.ansible/tmp/ansible-cloudformation\", line 2123, in \r\n import os, boto3\r\nImportError: No module named boto3\r\n", "parsed": false}
I did install boto3. python import boto3 does not give any error