Merge pull request #6154 from chaimann/fix-lookbook-still-missing

Fix install_lookbook step

Author: tvdeyen

admin/lib/generators/solidus_admin/install/install_generator.rb

@@ -38,7 +38,10 @@ def install_lookbook
           gem "actioncable"
         end
 
-        execute_command :bundle, :install
+        require 'bundler'
+        Bundler.with_unbundled_env do
+          execute_command :bundle, :install
+        end
 
         route "mount Lookbook::Engine, at: '#{solidus_mount_point}lookbook' if Rails.env.development?"
       end