```ruby
# coding: utf-8
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require 'rocktumbler/version'

Gem::Specification.new do |spec|
  spec.name          = 'rocktumbler'
  spec.version       = Rocktumbler::VERSION
  spec.authors       = ['Simon Reed']
  spec.email         = ['simonpreed@gmail.com']

  spec.summary       = 'Polish your Gemfile to make sure it remains consistent.'
  spec.description   = 'Polish your Gemfile to make sure it remains consistent.'
  spec.homepage      = 'https://github.com/simonreed/rocktumbler'
  spec.license       = 'MIT'

  spec.files         = `git ls-files -z`.split('\x0').reject { |f|
    f.match(%r{^(test|spec|features)/})
  }
  spec.executables   = %w(tumble)
  spec.require_paths = ['lib']

  spec.add_development_dependency 'rake', '~> 10.0'

  spec.add_runtime_dependency 'bundler', '~> 1.7'
end
```

Fix double quote issue in gemspec
user
```ruby
# coding: utf-8
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require 'rocktumbler/version'

Gem::Specification.new do |spec|
  spec.name          = 'rocktumbler'
  spec.version       = Rocktumbler::VERSION
  spec.authors       = ['Simon Reed']
  spec.email         = ['simonpreed@gmail.com']

  spec.summary       = 'Polish your Gemfile to make sure it remains consistent.'
  spec.description   = 'Polish your Gemfile to make sure it remains consistent.'
  spec.homepage      = 'https://github.com/simonreed/rocktumbler'
  spec.license       = 'MIT'

  spec.files         = `git ls-files -z`.split("\x0").reject { |f|
    f.match(%r{^(test|spec|features)/})
  }
  spec.executables   = %w(tumble)
  spec.require_paths = ['lib']

  spec.add_development_dependency 'rake', '~> 10.0'

  spec.add_runtime_dependency 'bundler', '~> 1.7'
end
```
assistant