Don’t crash if sprockets is absent
Don’t crash if sprockets is absent

Currently Webpacker has an implicit dependency on Sprockets. It enhances `assets:precompile` so trying to run any rake task will fail if webpacker is in the Gemfile but Sprockets hasn’t been initialized.

A good next step might be to define `assets:precompile` to `webpacker:compile` if the former is absent, for compatibility with existing tooling.

Davidzhu001/webpacker,shakacode/webpacker_lite,usertesting/webpacker,usertesting/webpacker,Davidzhu001/webpacker,rails/webpacker,gauravtiwari/webpacker,nickpith/webpacker,nickpith/webpacker,usertesting/webpacker,rossta/webpacker,rossta/webpacker,gauravtiwari/webpacker,rossta/webpacker,Davidzhu001/webpacker,rails/webpacker,gauravtiwari/webpacker,nickpith/webpacker,rossta/webpacker