Compatibility with sprockets-rails 3.0

[jhawthorn]

samanmohamadi helpfully points out in #609 that the handlebars_assets issue is fixed in their latest master.

After upgrading to that I have other asset issues:

ActionView::Template::Error:
  Asset was not declared to be precompiled in production.
  Add `Rails.application.config.assets.precompile += %w( logo/solidus_logo.png )` to `config/initializers/assets.rb` and restart your server
# /home/jhawthorn/src/solidus/core/app/helpers/spree/base_helper.rb:67:in `logo'

[jhawthorn]

Optimistically tagging this for 1.2. The sooner we sort this out the better

[Blackening999]

I strongly suggest to add a Troubleshooting section to README or consider hotfixes automatically merge to the master.
I've installed raw solidus gem (not bleeding edge pointing to github repo) and it's 1.1.0. The issue still the same.
I've lost 1 hour to find out the solution for that :\

Thank you

[tvdeyen]

It is very unfortunate that you lost an hour of your precious time.

What should a troubleshooting section in the README cover? Bugs like these happen and can have several causes. We really can't cover every potentially issue.

Debugging is annoying, cumbersome and frustrating, but explaining how to debug a Rails app can't be the purpose of this projects README.

There are lots of great resources out there covering debugging Rails apps.

What Solidus specific debugging advice should we add to the README?

[jhawthorn]

@Blackening999 sorry you lost time, but our latest release v1.1.1 does set an explicit dependency on the older sprockets-rails. There's not much more we can do than that to avoid issues.