Raise a useful error when reconnecting with a circuit breaker

[ccutrer]

If you have reconnects enabled, and a circuit breaker configured, it's useful to raise the actual underlying error when we actually attempted the connection instead of simply the circuit breaker error. The circuit breaker error will still be raised if no attempts were tried.

[byroot]

Some minor code style things, but otherwise LGTM.

[ccutrer]

Ping @byroot

[byroot]

Rubocop is angry again, but I'll fix it on master

[ccutrer]

Rubocop is angry again, but I'll fix it on master

Thanks, I appreciate it :).