Pyezviz

Change default value to none if camera doesn't support defense schedules.

-Fixed arg parser for camera status.
-Added method for defence schedule check. This isn't present on all cameras and resulted in errors.
-Small changes to public/private methods (Basically added _ to private methods as per PEP standard)

-Added refresh token support.
-Added Account credentials error messages. (on incorrect username or password)

Looks like ezviz is enforcing a captcha code. Was planning on moving to pure api login.

-Disabling/enabling of "defence" per camera doesn't work on this release yet.
-Can disable/enable on all cameras though via the switch_defence_mode api.

-Added new module that tests RTSP camera credentials. I'm planning on incorporating it on the Hass camera integration workflow.

-Checks correct API uri for non isolated regions with the default. (basically everything on the .ezvizlife.com domain)
-Fixed a few spelling and typos.
-Improved a few error messages.
-Added local ip to constants for HA sensor.