Add dev_dep for solidus_dev_support and require feature_helper

solidusio/solidus_support#28
Some files, this this feature_helper, were moved from solidus_support to
solidus_dev_support. This updates the testing requrie to get the file from the
correct place.

Author: harmonymjb

solidus_auth_devise.gemspec

@@ -51,6 +51,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency "shoulda-matchers", "~> 3.1"
   s.add_development_dependency "simplecov", "~> 0.14"
   s.add_development_dependency "solidus_backend", solidus_version
+  s.add_development_dependency "solidus_dev_support", ">= 0.3.0"
   s.add_development_dependency "solidus_frontend", solidus_version
   s.add_development_dependency "sqlite3"
 end

spec/spec_helper.rb

@@ -7,7 +7,8 @@
 
 require File.expand_path('dummy/config/environment.rb', __dir__)
 
-require "solidus_support/extension/feature_helper"
+require "solidus_dev_support"
+require "solidus_dev_support/rspec/feature_helper"
 
 Dir[File.join(File.dirname(__FILE__), "support/**/*.rb")].each { |f| require f }