Define handlers with port in name

[DavidWittman]

If this role is defined multiple times with parameterized variables (as in test/test_all.yml), the handler notification can cause some unexpected behaviors due to namespace overlap. Because the handlers are all named the same (e.g. restart redis or restart sentinel), multiple role inclusions define the handler the same. When those handlers are later notified, only the handler from the first inclusion is run.

The behavior is much better documented in this issue:

ansible/ansible#4853

To fix, change the handler name to restart redis {{ redis_port }} and restart sentinel {{ redis_sentinel_port }}. We may need to bump the minimum Ansible version in response to this issue.