find_admins KeyError

```
(cloudmapper) root@f9efb2165ca6:/opt/cloudmapper# python cloudmapper.py find_admins --account YOUR_ACCOUNT
Traceback (most recent call last):
File "cloudmapper.py", line 72, in
main()
File "cloudmapper.py", line 66, in main
commands[command].run(arguments)
File "/opt/cloudmapper/commands/find_admins.py", line 31, in run
admins = find_admins(accounts, args, findings=set())
File "/opt/cloudmapper/shared/iam_audit.py", line 147, in find_admins
region, findings, privs_to_look_for, include_restricted
File "/opt/cloudmapper/shared/iam_audit.py", line 276, in find_admins_in_account
policy["Arn"],
KeyError: 'Arn'
```