Fix rubygems source code location metadata.

Author: dblock

grape-swagger-rails.gemspec

@@ -9,13 +9,18 @@ Gem::Specification.new do |spec|
   spec.version       = GrapeSwaggerRails::VERSION
   spec.authors       = ['Alexander Logunov']
   spec.email         = ['unlovedru@gmail.com']
-  spec.description   = 'Swagger UI as Rails Engine for grape-swagger gem'
-  spec.summary       = 'Swagger UI as Rails Engine for grape-swagger gem'
+  spec.description   = 'Swagger UI as Rails Engine for grape-swagger gem.'
+  spec.summary       = 'Swagger UI as Rails Engine for grape-swagger gem.'
   spec.homepage      = 'https://github.com/ruby-grape/grape-swagger-rails'
   spec.license       = 'MIT'
   spec.files         = `git ls-files`.split($INPUT_RECORD_SEPARATOR)
   spec.test_files    = `git ls-files spec`.split($INPUT_RECORD_SEPARATOR)
   spec.require_paths = %w[lib]
-
   spec.add_dependency 'railties', '>= 6.0.6.1'
+  spec.metadata = {
+    'bug_tracker_uri' => 'https://github.com/ruby-grape/grape-swagger-rails/issues',
+    'changelog_uri' => 'https://github.com/ruby-grape/grape-swagger-rails/blob/master/CHANGELOG.md',
+    'source_code_uri' => "https://github.com/ruby-grape/grape-swagger-rails/tree/v#{version}",
+    'rubygems_mfa_required' => 'true'
+  }
 end