Adapt to Sprockets 4

[cohei]

calling non-existent method 'pathname'
#88

[mattbrictson]

This looks like a good fix. I'm curious, why did you close it?

[cohei]

I intended internal use but made this pull request by mistake. So I didn't check enough. For example, whether it still works on sprockets 3.

The change is just from #88. You can open a new pull request with the same change by looking that if you want.

However, there is no big reason for closing this. Well, I'll reopen it.

[KevinBongart]

@mattbrictson @brentd Let's get this bugfix in? One-liner that fixes an issue with Sprockets 4 which is getting more and more adoption with Rails 6.0.1 out.

[mattbrictson]

Thanks for the fix!

[arman-h]

Would you mind making a release with this bugfix in it? It would be useful to get this for apps running Rails 6. The last release (0.3.2) was almost a year ago.

[mattbrictson]

Unfortunately this PR does not completely provide compatibility with Rails 6 and Sprockets 4. See discussion at #88 (comment) and #105.

The current release of xray-rails (0.3.2) does work with Rails 6, as long as you pin to sprockets ~> 3.5.