Update Gemfile for engine_cart 0.8.0

Gemfile

@@ -12,18 +12,29 @@ group :test do
   gem 'activerecord-jdbcsqlite3-adapter', :platform => :jruby
 end
 
-file = File.expand_path("Gemfile", ENV['ENGINE_CART_DESTINATION'] || ENV['RAILS_ROOT'] || File.expand_path("../spec/internal", __FILE__))
-if File.exists?(file)
-  puts "Loading #{file} ..." if $DEBUG # `ruby -d` or `bundle -v`
-  instance_eval File.read(file)
+# BEGIN ENGINE_CART BLOCK
+# engine_cart: 0.8.0
+# engine_cart stanza: 0.8.0
+# the below comes from engine_cart, a gem used to test this Rails engine gem in the context of a Rails app.
+file = File.expand_path("Gemfile", ENV['ENGINE_CART_DESTINATION'] || ENV['RAILS_ROOT'] || File.expand_path(".internal_test_app", File.dirname(__FILE__)))
+if File.exist?(file)
+  begin
+    eval_gemfile file
+  rescue Bundler::GemfileError => e
+    Bundler.ui.warn '[EngineCart] Skipping Rails application dependencies:'
+    Bundler.ui.warn e.message
+  end
 else
+  Bundler.ui.warn "[EngineCart] Unable to find test application dependencies in #{file}, using placeholder dependencies"
+
   gem 'rails', ENV['RAILS_VERSION'] if ENV['RAILS_VERSION']
 
-  if ENV['RAILS_VERSION'].nil? || ENV['RAILS_VERSION'] > "4.2"
+  if ENV['RAILS_VERSION'].nil? || ENV['RAILS_VERSION'] =~ /^4.2/
     gem 'responders', "~> 2.0"
     gem 'sass-rails', ">= 5.0"
   else
     gem 'bootstrap-sass', '< 3.3.5' # 3.3.5 requires sass 3.3, incompatible with sass-rails 4.x
     gem 'sass-rails', "< 5.0"
   end
 end
+# END ENGINE_CART BLOCK