Nmap log messages

In my Home assistant log, I’m seeing a lot of these messages:

2019-03-14 11:18:59 INFO (SyncWorker_19) [homeassistant.components.device_tracker.nmap_tracker] Scanning...
2019-03-14 11:18:59 INFO (SyncWorker_19) [homeassistant.components.device_tracker.nmap_tracker] nmap scan successful
2019-03-14 11:19:12 INFO (SyncWorker_17) [homeassistant.components.device_tracker.nmap_tracker] Scanning...
2019-03-14 11:19:12 INFO (SyncWorker_17) [homeassistant.components.device_tracker.nmap_tracker] nmap scan successful

Propose to move these log messages from INFO to DEBUG. So they don’t clutter up my logging.
They don’t give much information anyway.

https://github.com/home-assistant/home-assistant/pull/22036