fix(interceptor): check config in responseError

[PatrickJS]

sometimes there are http rejects without config objects from other interceptors

[lord2800]

Those other interceptors are the problem--config should always be an object. See #50.

[PatrickJS]

if that's the throwing an error with that explanation would be a lot more beneficial and prevent the same PR from happening

[chieffancypants]

Thanks for the help @lord2800!

This certainly does seem to come up quite a lot, but I've never been fond of the idea of adding code here to detect problems in other projects. Throwing an error would be perfect if the error wasn't intermittent, but as it is, it could cause more issues than simply ignoring the problem in the first place.

Perhaps $logging the error would help bring awareness to poorly implemented interceptors, while allowing the app to remain operational?

[PatrickJS]

Here is a PR for the log so others can fix their repo #133