updated to work with the environmental variables if available.

tasks/main.yml

diff --git a/tasks/main.yml b/tasks/main.yml
index c81eb2d..84f137f 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -10,7 +10,7 @@
     instance_ids: '{{ ansible_ec2_instance_id }}'
     aws_access_key: "{{ aws_access_key|default(lookup('env', 'AWS_ACCESS_KEY_ID')) }}"
     aws_secret_key: "{{ aws_secret_key|default(lookup('env', 'AWS_SECRET_ACCESS_KEY')) }}"
-    aws_region: '{{ aws_region }}'
+    aws_region: "{{ aws_region|default(lookup('env', 'AWS_REGION'))  }}"
 
 - name: Terminate AMI instances status report
   debug: