* iam_role: Add support for managing MaxSessionDuration
* iam_role: Add support for deleting the IAM Instance Profiles we created
* iam_role: migrate all boto failures to fail_json_aws for consistency
* iam_role: test validity of path so we can throw a more understandable error
* iam_role: (integration tests) Split iam_role integration tests from sts_assume_role tests
- Make the iam_role tests more comprehensive
- Add tests for iam_role_info
* iam_role: (integration tests) Make some of our pauses optional
If the tests appear to be flakey we may need to enable standard_pauses
