Depend on railties and sprockets-rails gems instead of rails gem

Author: deepj

jsbundling-rails.gemspec

@@ -11,5 +11,6 @@ Gem::Specification.new do |spec|
 
   spec.files = Dir["lib/**/*", "MIT-LICENSE", "README.md"]
 
-  spec.add_dependency "rails", ">= 6.0.0"
+  spec.add_dependency "railties", ">= 6.0.0"
+  spec.add_dependency "sprockets-rails", ">= 2.0.0"
 end