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

Gem::Specification.new do |spec|
  spec.name          = "metasploit-erd"
  spec.version       = Metasploit::ERD::VERSION
  spec.authors       = ["Luke Imhoff"]
  spec.email         = ["luke_imhoff@rapid7.com"]
  spec.summary       = %q{TODO: Write a short summary. Required.}
  spec.description   = %q{TODO: Write a longer description. Optional.}
  spec.homepage      = ""
  spec.license       = "MIT"

  spec.files         = `git ls-files -z`.split("\x0")
  spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
  spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
  spec.require_paths = ["lib"]

  spec.add_development_dependency "bundler", "~> 1.5"
  spec.add_development_dependency "rake"
  spec.add_development_dependency "rspec"
end
```

Add semantic version restrictions to gemspec
user
```ruby
# coding: utf-8
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require 'metasploit/erd/version'

Gem::Specification.new do |spec|
  spec.name          = 'metasploit-erd'
  spec.version       = Metasploit::ERD::VERSION
  spec.authors       = ['Luke Imhoff']
  spec.email         = ['luke_imhoff@rapid7.com']
  spec.summary       = 'Extensions to rails-erd to find clusters of models to generate subdomains specific to each model'
  spec.description   = 'Traces the belongs_to associations on ActiveRecord::Base descendants to find the minimum ' \
                       'cluster in which all foreign keys are fulfilled in the Entity-Relationship Diagram.'
  spec.homepage      = 'https://github.com/rapid7/metasploit-erd'
  spec.license       = "MIT"

  spec.files         = `git ls-files -z`.split("\x0")
  spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
  spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
  spec.require_paths = ['lib']

  spec.add_development_dependency 'bundler', '~> 1.5'
  spec.add_development_dependency 'rake', '~> 10.3'
  spec.add_development_dependency 'rspec', '~> 2.14'
end
```
assistant