Report a simple error count / warrning count / Issues count

[IronTooch]

So, in order to use Ansible-Lint as a mechanism to feed APIs or other features, it would be nice if we could get some more command line options. Things like error count, warning count, etc are already available, and issues would just be error + warning.

ansible-lint --error-count
3

ansible-lint --warning-count
2

ansible-lint --issues-count
5