Set request object on axios errors

[devinpitcher]

Fixes #168

Adds the request object to the error. This is important and follows the way that Axios handles errors.

[gilbsgilbs]

Shouldn't this be responseURL and not responseUrl. I least in my browser URL is uppercased. (see #287)

[marcbachmann]

I don't think there's an easy way to support that correctly.
error.request is the original outgoing request based on the adapter implementation.

require('axios').get('https://example.com/foo').catch((err) => console.error(err.request.url))
> undefined

require('axios').get('https://example.com/foo').catch((err) => console.error(err.request.responseURL))
> undefined

require('axios').get('https://example.com/foo').catch((err) => console.error(err.request.responseUrl))
> undefined

require('axios').get('https://example.com/foo', {adapter: 'fetch'}).catch((err) => console.error(err.request.url))
> 'https://example.com/foo'

responseUrl or responseURL both don't exist at least on node.