Move development dependencies to Gemfile

Author: rgrove

Gemfile

@@ -2,3 +2,9 @@
 
 source "https://rubygems.org"
 gemspec
+
+group :development do
+  gem "bundler", "~> 2.6.2"
+  gem "minitest", "5.25.4"
+  gem "rake", "13.2.1"
+end

sanitize.gemspec

@@ -25,14 +25,9 @@ Gem::Specification.new do |s|
     'documentation_uri' => 'https://rubydoc.info/github/rgrove/sanitize'
   }
 
-  # Runtime dependencies.
   s.add_dependency('crass', '~> 1.0.2')
   s.add_dependency('nokogiri', '>= 1.16.8')
 
-  # Development dependencies.
-  s.add_development_dependency('minitest', '~> 5.25.4')
-  s.add_development_dependency('rake', '~> 13.2.1')
-
   s.require_paths = ['lib']
 
   s.files = [