Does `solid_queue` depend on the whole Rails stack?

[nimmolo]

Hi @rosa - we'd love to try out solid_queue in production, but our app does not need to load ActiveStorage, ActionText or ActionMailbox. I think it's pretty common for people to just use some Rails gems.

Would you accept a simple PR #158 adjusting the solid_queue.gemspec so it doesn't require all of rails as a dependency? Including just railties and necessary gems is how they do it in the gemspec for solid_cache too.

solid_queue seems to only need part of the stack. :

# solid_queue/bin/rails

require "rails"
# Pick the frameworks you want:
require "active_model/railtie"
require "active_job/railtie"
require "active_record/railtie"
# require "active_storage/engine"
require "action_controller/railtie"
# require "action_mailer/railtie"
require "action_view/railtie"
# require "action_cable/engine"
require "rails/test_unit/railtie"
require "rails/engine/commands"

[jeremy]

Continued in #158