```ruby
Gem::Specification.new do |spec|
  spec.name          = 'sensu-extensions-statsd'
  spec.version       = '2.0.0'
  spec.authors       = ['Sensu-Extensions and contributors']
  spec.email         = ['<sensu-users@googlegroups.com>']

  spec.summary       = 'Check extension to run a StatsD implementation'
  spec.description   = 'Check extension to run a StatsD implementation'
  spec.homepage      = 'https://github.com/sensu-extensions/sensu-extensions-statsd'

  spec.files         = Dir.glob('{bin,lib}/**/*') + %w[LICENSE README.md CHANGELOG.md] # rubocop:disable Metrics/LineLength
  spec.require_paths = ['lib']

  spec.add_dependency 'sensu-extension'

  spec.add_development_dependency 'bundler', '~> 1.6'
  spec.add_development_dependency 'github_changelog_generator'
  spec.add_development_dependency 'rake'
  spec.add_development_dependency 'rspec'
  spec.add_development_dependency 'rubocop', '~> 0.57.2'
  spec.add_development_dependency 'sensu-logger'
  spec.add_development_dependency 'sensu-settings'

  spec.required_ruby_version = '>= 2.1.0'
end
```

Update bundler requirement from ~> 1.6 to ~> 2.1
user
```ruby
Gem::Specification.new do |spec|
  spec.name          = 'sensu-extensions-statsd'
  spec.version       = '2.0.0'
  spec.authors       = ['Sensu-Extensions and contributors']
  spec.email         = ['<sensu-users@googlegroups.com>']

  spec.summary       = 'Check extension to run a StatsD implementation'
  spec.description   = 'Check extension to run a StatsD implementation'
  spec.homepage      = 'https://github.com/sensu-extensions/sensu-extensions-statsd'

  spec.files         = Dir.glob('{bin,lib}/**/*') + %w[LICENSE README.md CHANGELOG.md] # rubocop:disable Metrics/LineLength
  spec.require_paths = ['lib']

  spec.add_dependency 'sensu-extension'

  spec.add_development_dependency 'bundler', '~> 2.1'
  spec.add_development_dependency 'github_changelog_generator'
  spec.add_development_dependency 'rake'
  spec.add_development_dependency 'rspec'
  spec.add_development_dependency 'rubocop', '~> 0.57.2'
  spec.add_development_dependency 'sensu-logger'
  spec.add_development_dependency 'sensu-settings'

  spec.required_ruby_version = '>= 2.1.0'
end
```
assistant