```ruby
Gem::Specification.new do |s|
  s.platform    = Gem::Platform::RUBY
  s.name        = 'spree_product_assembly'
  s.version     = '1.0.0'
  s.summary     = 'Adds oportunity to make bundle of products to your Spree store'
  s.description = 'Adds oportunity to make bundle of products to your Spree store'
  s.required_ruby_version = '>= 1.8.7'

  s.author            = 'Roman Smirnov'
  s.email             = 'roman@railsdog.com'
  s.homepage          = 'https://github.com/spree/spree-product-assembly'
  # s.rubyforge_project = 'actionmailer'

  s.files         = `git ls-files`.split("\n")
  s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")
  s.require_path = 'lib'
  s.requirements << 'none'

  s.add_dependency('spree', '~> 1.0')
  
  s.add_development_dependency 'rspec-rails',  '~> 2.7'
  s.add_development_dependency 'sqlite3'
  s.add_development_dependency 'ffaker'
  s.add_development_dependency 'factory_girl', '~> 2.6'
end
  ```

Allow any Spree 2.0.0 version
user
```ruby
Gem::Specification.new do |s|
  s.platform    = Gem::Platform::RUBY
  s.name        = 'spree_product_assembly'
  s.version     = '1.0.0'
  s.summary     = 'Adds oportunity to make bundle of products to your Spree store'
  s.description = 'Adds oportunity to make bundle of products to your Spree store'
  s.required_ruby_version = '>= 1.8.7'

  s.author            = 'Roman Smirnov'
  s.email             = 'roman@railsdog.com'
  s.homepage          = 'https://github.com/spree/spree-product-assembly'
  # s.rubyforge_project = 'actionmailer'

  s.files         = `git ls-files`.split("\n")
  s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")
  s.require_path = 'lib'
  s.requirements << 'none'

  s.add_dependency('spree', '~> 2.0.0')
  
  s.add_development_dependency 'rspec-rails',  '~> 2.7'
  s.add_development_dependency 'sqlite3'
  s.add_development_dependency 'ffaker'
  s.add_development_dependency 'factory_girl', '~> 2.6'
end
  ```
assistant