Sprockets 3.7 warning about deprecated method `register_engine`

[gambala]

Got this message after updating sprockets gem from 3.6.2 to 3.7.0:

01 DEPRECATION WARNING: Sprockets method `register_engine` is deprecated.
01 Please register a mime type using `register_mime_type` then
01 use `register_compressor` or `register_transformer`.
01 https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md#supporting-all-versions-of-sprockets-in-processors
01  (called from setup at /home/deployer/apps/gambala/shared/bundle/ruby/2.3.0/gems/stylus-1.0.1/lib/stylus/sprockets.rb:42)

And this:

01 DEPRECATION WARNING: You are using the a deprecated processor interface Stylus::ImportProcessor.
01 Please update your processor interface:
01 https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md#supporting-all-versions-of-sprockets-in-processors
01  (called from setup at /home/deployer/apps/gambala/shared/bundle/ruby/2.3.0/gems/stylus-1.0.1/lib/stylus/sprockets.rb:43)

Use Rails (5.0.0), and stylus gem (both rubygems 1.0.1 version and github master version give me these warnings).

[cmtonkinson]

I can confirm this is a problem moving to Sprockets 4. Gladly welcoming PRs resolving this issue.

Reference here: https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md#registering-all-versions-of-sprockets-in-processors

Also (and YMMV) it looks like locking sprockets to 3.6.3 (per rails/sass-rails#381 (comment)) may provide a temporary workaround.