CeleryPingHealthCheck is catching BaseException and really, *really*, **really** shouldn't 😄

[violuke]

There was some discussion on this in #240 and I really strongly disagree with the idea of catching BaseException (or even Exception for that matter), and I'm not alone.

We've had to remove this check and re-implement our own, which is much the same as this package's check but doesn't catch the BaseException. There might be some other errors to catch, like #340 does for CacheBackend, but they really should be caught properly and not just caught via BaseException.

I must also say Thank You to everyone who maintains this package, it really is very helpful for us 😄