* Improve iam_group exception handling
Use AnsibleAWSModule for iam_group and handle BotoCoreErrors
as well as ClientErrors. Use fail_json_aws to improve error messages
* Add minimal iam_group test suite
Update some of the read-only IAM permissions (this is not sufficient
to run the test suite but it gets further than it did until it tries
to add a (non-existent) user)
* Clean up after tests
* added account_alias in the response of module aws_caller_facts
* added comment to explain list_account_aliases
* renamed caller_identity to caller_facts as the content is extended
* created changelog
* security-policy needs the iam:ListAccountAliases for this module to work
* test now checks for the added field account_alias
* gracefully handle missing iam:ListAccountAliases permission
Tests for:
* ecs_cluster
* ecs_service
* ecs_service_facts
* ecs_taskdefinition
* ecs_taskdefinition_facts
* Add idempotency testing
Test ecs_cluster, ecs_service and ecs_taskdefinition for trivial
idempotency. Add FIXMEs to the tests because the latter two fail.
Remove unused dependencies
